Restore numerics headers from release 4137

diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/checked_math.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/checked_math.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/checked_math.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/checked_math.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,395 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_H_
-#define THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_H_
-
-#include <stddef.h>
-
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/checked_math_impl.h"
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-template <typename T>
-class CheckedNumeric {
-  static_assert(std::is_arithmetic<T>::value,
-                "CheckedNumeric<T>: T must be a numeric type.");
-
- public:
-  using type = T;
-
-  constexpr CheckedNumeric() = default;
-
-  // Copy constructor.
-  template <typename Src>
-  constexpr CheckedNumeric(const CheckedNumeric<Src>& rhs)
-      : state_(rhs.state_.value(), rhs.IsValid()) {}
-
-  template <typename Src>
-  friend class CheckedNumeric;
-
-  // This is not an explicit constructor because we implicitly upgrade regular
-  // numerics to CheckedNumerics to make them easier to use.
-  template <typename Src>
-  constexpr CheckedNumeric(Src value)  // NOLINT(runtime/explicit)
-      : state_(value) {
-    static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
-  }
-
-  // This is not an explicit constructor because we want a seamless conversion
-  // from StrictNumeric types.
-  template <typename Src>
-  constexpr CheckedNumeric(
-      StrictNumeric<Src> value)  // NOLINT(runtime/explicit)
-      : state_(static_cast<Src>(value)) {}
-
-  // IsValid() - The public API to test if a CheckedNumeric is currently valid.
-  // A range checked destination type can be supplied using the Dst template
-  // parameter.
-  template <typename Dst = T>
-  constexpr bool IsValid() const {
-    return state_.is_valid() &&
-           IsValueInRangeForNumericType<Dst>(state_.value());
-  }
-
-  // AssignIfValid(Dst) - Assigns the underlying value if it is currently valid
-  // and is within the range supported by the destination type. Returns true if
-  // successful and false otherwise.
-  template <typename Dst>
-#if defined(__clang__) || defined(__GNUC__)
-  __attribute__((warn_unused_result))
-#elif defined(_MSC_VER)
-  _Check_return_
-#endif
-  constexpr bool
-  AssignIfValid(Dst* result) const {
-    return BASE_NUMERICS_LIKELY(IsValid<Dst>())
-               ? ((*result = static_cast<Dst>(state_.value())), true)
-               : false;
-  }
-
-  // ValueOrDie() - The primary accessor for the underlying value. If the
-  // current state is not valid it will CHECK and crash.
-  // A range checked destination type can be supplied using the Dst template
-  // parameter, which will trigger a CHECK if the value is not in bounds for
-  // the destination.
-  // The CHECK behavior can be overridden by supplying a handler as a
-  // template parameter, for test code, etc. However, the handler cannot access
-  // the underlying value, and it is not available through other means.
-  template <typename Dst = T, class CheckHandler = CheckOnFailure>
-  constexpr StrictNumeric<Dst> ValueOrDie() const {
-    return BASE_NUMERICS_LIKELY(IsValid<Dst>())
-               ? static_cast<Dst>(state_.value())
-               : CheckHandler::template HandleFailure<Dst>();
-  }
-
-  // ValueOrDefault(T default_value) - A convenience method that returns the
-  // current value if the state is valid, and the supplied default_value for
-  // any other state.
-  // A range checked destination type can be supplied using the Dst template
-  // parameter. WARNING: This function may fail to compile or CHECK at runtime
-  // if the supplied default_value is not within range of the destination type.
-  template <typename Dst = T, typename Src>
-  constexpr StrictNumeric<Dst> ValueOrDefault(const Src default_value) const {
-    return BASE_NUMERICS_LIKELY(IsValid<Dst>())
-               ? static_cast<Dst>(state_.value())
-               : checked_cast<Dst>(default_value);
-  }
-
-  // Returns a checked numeric of the specified type, cast from the current
-  // CheckedNumeric. If the current state is invalid or the destination cannot
-  // represent the result then the returned CheckedNumeric will be invalid.
-  template <typename Dst>
-  constexpr CheckedNumeric<typename UnderlyingType<Dst>::type> Cast() const {
-    return *this;
-  }
-
-  // This friend method is available solely for providing more detailed logging
-  // in the the tests. Do not implement it in production code, because the
-  // underlying values may change at any time.
-  template <typename U>
-  friend U GetNumericValueForTest(const CheckedNumeric<U>& src);
-
-  // Prototypes for the supported arithmetic operator overloads.
-  template <typename Src>
-  constexpr CheckedNumeric& operator+=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator-=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator*=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator/=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator%=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator<<=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator>>=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator&=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator|=(const Src rhs);
-  template <typename Src>
-  constexpr CheckedNumeric& operator^=(const Src rhs);
-
-  constexpr CheckedNumeric operator-() const {
-    // The negation of two's complement int min is int min, so we simply
-    // check for that in the constexpr case.
-    // We use an optimized code path for a known run-time variable.
-    return MustTreatAsConstexpr(state_.value()) || !std::is_signed<T>::value ||
-                   std::is_floating_point<T>::value
-               ? CheckedNumeric<T>(
-                     NegateWrapper(state_.value()),
-                     IsValid() && (!std::is_signed<T>::value ||
-                                   std::is_floating_point<T>::value ||
-                                   NegateWrapper(state_.value()) !=
-                                       std::numeric_limits<T>::lowest()))
-               : FastRuntimeNegate();
-  }
-
-  constexpr CheckedNumeric operator~() const {
-    return CheckedNumeric<decltype(InvertWrapper(T()))>(
-        InvertWrapper(state_.value()), IsValid());
-  }
-
-  constexpr CheckedNumeric Abs() const {
-    return !IsValueNegative(state_.value()) ? *this : -*this;
-  }
-
-  template <typename U>
-  constexpr CheckedNumeric<typename MathWrapper<CheckedMaxOp, T, U>::type> Max(
-      const U rhs) const {
-    using R = typename UnderlyingType<U>::type;
-    using result_type = typename MathWrapper<CheckedMaxOp, T, U>::type;
-    // TODO(jschuh): This can be converted to the MathOp version and remain
-    // constexpr once we have C++14 support.
-    return CheckedNumeric<result_type>(
-        static_cast<result_type>(
-            IsGreater<T, R>::Test(state_.value(), Wrapper<U>::value(rhs))
-                ? state_.value()
-                : Wrapper<U>::value(rhs)),
-        state_.is_valid() && Wrapper<U>::is_valid(rhs));
-  }
-
-  template <typename U>
-  constexpr CheckedNumeric<typename MathWrapper<CheckedMinOp, T, U>::type> Min(
-      const U rhs) const {
-    using R = typename UnderlyingType<U>::type;
-    using result_type = typename MathWrapper<CheckedMinOp, T, U>::type;
-    // TODO(jschuh): This can be converted to the MathOp version and remain
-    // constexpr once we have C++14 support.
-    return CheckedNumeric<result_type>(
-        static_cast<result_type>(
-            IsLess<T, R>::Test(state_.value(), Wrapper<U>::value(rhs))
-                ? state_.value()
-                : Wrapper<U>::value(rhs)),
-        state_.is_valid() && Wrapper<U>::is_valid(rhs));
-  }
-
-  // This function is available only for integral types. It returns an unsigned
-  // integer of the same width as the source type, containing the absolute value
-  // of the source, and properly handling signed min.
-  constexpr CheckedNumeric<typename UnsignedOrFloatForSize<T>::type>
-  UnsignedAbs() const {
-    return CheckedNumeric<typename UnsignedOrFloatForSize<T>::type>(
-        SafeUnsignedAbs(state_.value()), state_.is_valid());
-  }
-
-  constexpr CheckedNumeric& operator++() {
-    *this += 1;
-    return *this;
-  }
-
-  constexpr CheckedNumeric operator++(int) {
-    CheckedNumeric value = *this;
-    *this += 1;
-    return value;
-  }
-
-  constexpr CheckedNumeric& operator--() {
-    *this -= 1;
-    return *this;
-  }
-
-  constexpr CheckedNumeric operator--(int) {
-    CheckedNumeric value = *this;
-    *this -= 1;
-    return value;
-  }
-
-  // These perform the actual math operations on the CheckedNumerics.
-  // Binary arithmetic operations.
-  template <template <typename, typename, typename> class M,
-            typename L,
-            typename R>
-  static constexpr CheckedNumeric MathOp(const L lhs, const R rhs) {
-    using Math = typename MathWrapper<M, L, R>::math;
-    T result = 0;
-    bool is_valid =
-        Wrapper<L>::is_valid(lhs) && Wrapper<R>::is_valid(rhs) &&
-        Math::Do(Wrapper<L>::value(lhs), Wrapper<R>::value(rhs), &result);
-    return CheckedNumeric<T>(result, is_valid);
-  }
-
-  // Assignment arithmetic operations.
-  template <template <typename, typename, typename> class M, typename R>
-  constexpr CheckedNumeric& MathOp(const R rhs) {
-    using Math = typename MathWrapper<M, T, R>::math;
-    T result = 0;  // Using T as the destination saves a range check.
-    bool is_valid = state_.is_valid() && Wrapper<R>::is_valid(rhs) &&
-                    Math::Do(state_.value(), Wrapper<R>::value(rhs), &result);
-    *this = CheckedNumeric<T>(result, is_valid);
-    return *this;
-  }
-
- private:
-  CheckedNumericState<T> state_;
-
-  CheckedNumeric FastRuntimeNegate() const {
-    T result;
-    bool success = CheckedSubOp<T, T>::Do(T(0), state_.value(), &result);
-    return CheckedNumeric<T>(result, IsValid() && success);
-  }
-
-  template <typename Src>
-  constexpr CheckedNumeric(Src value, bool is_valid)
-      : state_(value, is_valid) {}
-
-  // These wrappers allow us to handle state the same way for both
-  // CheckedNumeric and POD arithmetic types.
-  template <typename Src>
-  struct Wrapper {
-    static constexpr bool is_valid(Src) { return true; }
-    static constexpr Src value(Src value) { return value; }
-  };
-
-  template <typename Src>
-  struct Wrapper<CheckedNumeric<Src>> {
-    static constexpr bool is_valid(const CheckedNumeric<Src> v) {
-      return v.IsValid();
-    }
-    static constexpr Src value(const CheckedNumeric<Src> v) {
-      return v.state_.value();
-    }
-  };
-
-  template <typename Src>
-  struct Wrapper<StrictNumeric<Src>> {
-    static constexpr bool is_valid(const StrictNumeric<Src>) { return true; }
-    static constexpr Src value(const StrictNumeric<Src> v) {
-      return static_cast<Src>(v);
-    }
-  };
-};
-
-// Convenience functions to avoid the ugly template disambiguator syntax.
-template <typename Dst, typename Src>
-constexpr bool IsValidForType(const CheckedNumeric<Src> value) {
-  return value.template IsValid<Dst>();
-}
-
-template <typename Dst, typename Src>
-constexpr StrictNumeric<Dst> ValueOrDieForType(
-    const CheckedNumeric<Src> value) {
-  return value.template ValueOrDie<Dst>();
-}
-
-template <typename Dst, typename Src, typename Default>
-constexpr StrictNumeric<Dst> ValueOrDefaultForType(
-    const CheckedNumeric<Src> value,
-    const Default default_value) {
-  return value.template ValueOrDefault<Dst>(default_value);
-}
-
-// Convience wrapper to return a new CheckedNumeric from the provided arithmetic
-// or CheckedNumericType.
-template <typename T>
-constexpr CheckedNumeric<typename UnderlyingType<T>::type> MakeCheckedNum(
-    const T value) {
-  return value;
-}
-
-// These implement the variadic wrapper for the math operations.
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R>
-constexpr CheckedNumeric<typename MathWrapper<M, L, R>::type> CheckMathOp(
-    const L lhs,
-    const R rhs) {
-  using Math = typename MathWrapper<M, L, R>::math;
-  return CheckedNumeric<typename Math::result_type>::template MathOp<M>(lhs,
-                                                                        rhs);
-}
-
-// General purpose wrapper template for arithmetic operations.
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R,
-          typename... Args>
-constexpr CheckedNumeric<typename ResultType<M, L, R, Args...>::type>
-CheckMathOp(const L lhs, const R rhs, const Args... args) {
-  return CheckMathOp<M>(CheckMathOp<M>(lhs, rhs), args...);
-}
-
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Add, +, +=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Sub, -, -=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Mul, *, *=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Div, /, /=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Mod, %, %=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Lsh, <<, <<=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Rsh, >>, >>=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, And, &, &=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Or, |, |=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Checked, Check, Xor, ^, ^=)
-BASE_NUMERIC_ARITHMETIC_VARIADIC(Checked, Check, Max)
-BASE_NUMERIC_ARITHMETIC_VARIADIC(Checked, Check, Min)
-
-// These are some extra StrictNumeric operators to support simple pointer
-// arithmetic with our result types. Since wrapping on a pointer is always
-// bad, we trigger the CHECK condition here.
-template <typename L, typename R>
-L* operator+(L* lhs, const StrictNumeric<R> rhs) {
-  uintptr_t result = CheckAdd(reinterpret_cast<uintptr_t>(lhs),
-                              CheckMul(sizeof(L), static_cast<R>(rhs)))
-                         .template ValueOrDie<uintptr_t>();
-  return reinterpret_cast<L*>(result);
-}
-
-template <typename L, typename R>
-L* operator-(L* lhs, const StrictNumeric<R> rhs) {
-  uintptr_t result = CheckSub(reinterpret_cast<uintptr_t>(lhs),
-                              CheckMul(sizeof(L), static_cast<R>(rhs)))
-                         .template ValueOrDie<uintptr_t>();
-  return reinterpret_cast<L*>(result);
-}
-
-}  // namespace internal
-
-using internal::CheckedNumeric;
-using internal::IsValidForType;
-using internal::ValueOrDieForType;
-using internal::ValueOrDefaultForType;
-using internal::MakeCheckedNum;
-using internal::CheckMax;
-using internal::CheckMin;
-using internal::CheckAdd;
-using internal::CheckSub;
-using internal::CheckMul;
-using internal::CheckDiv;
-using internal::CheckMod;
-using internal::CheckLsh;
-using internal::CheckRsh;
-using internal::CheckAnd;
-using internal::CheckOr;
-using internal::CheckXor;
-
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/checked_math_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/checked_math_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/checked_math_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/checked_math_impl.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,579 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_IMPL_H_
-#define THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_IMPL_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <climits>
-#include <cmath>
-#include <cstdlib>
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/safe_conversions.h"
-#include "third_party/base/numerics/safe_math_shared_impl.h"
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-template <typename T>
-constexpr bool CheckedAddImpl(T x, T y, T* result) {
-  static_assert(std::is_integral<T>::value, "Type must be integral");
-  // Since the value of x+y is undefined if we have a signed type, we compute
-  // it using the unsigned type of the same size.
-  using UnsignedDst = typename std::make_unsigned<T>::type;
-  using SignedDst = typename std::make_signed<T>::type;
-  UnsignedDst ux = static_cast<UnsignedDst>(x);
-  UnsignedDst uy = static_cast<UnsignedDst>(y);
-  UnsignedDst uresult = static_cast<UnsignedDst>(ux + uy);
-  *result = static_cast<T>(uresult);
-  // Addition is valid if the sign of (x + y) is equal to either that of x or
-  // that of y.
-  return (std::is_signed<T>::value)
-             ? static_cast<SignedDst>((uresult ^ ux) & (uresult ^ uy)) >= 0
-             : uresult >= uy;  // Unsigned is either valid or underflow.
-}
-
-template <typename T, typename U, class Enable = void>
-struct CheckedAddOp {};
-
-template <typename T, typename U>
-struct CheckedAddOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    // TODO(jschuh) Make this "constexpr if" once we're C++17.
-    if (CheckedAddFastOp<T, U>::is_supported)
-      return CheckedAddFastOp<T, U>::Do(x, y, result);
-
-    // Double the underlying type up to a full machine word.
-    using FastPromotion = typename FastIntegerArithmeticPromotion<T, U>::type;
-    using Promotion =
-        typename std::conditional<(IntegerBitsPlusSign<FastPromotion>::value >
-                                   IntegerBitsPlusSign<intptr_t>::value),
-                                  typename BigEnoughPromotion<T, U>::type,
-                                  FastPromotion>::type;
-    // Fail if either operand is out of range for the promoted type.
-    // TODO(jschuh): This could be made to work for a broader range of values.
-    if (BASE_NUMERICS_UNLIKELY(!IsValueInRangeForNumericType<Promotion>(x) ||
-                               !IsValueInRangeForNumericType<Promotion>(y))) {
-      return false;
-    }
-
-    Promotion presult = {};
-    bool is_valid = true;
-    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
-      presult = static_cast<Promotion>(x) + static_cast<Promotion>(y);
-    } else {
-      is_valid = CheckedAddImpl(static_cast<Promotion>(x),
-                                static_cast<Promotion>(y), &presult);
-    }
-    *result = static_cast<V>(presult);
-    return is_valid && IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-template <typename T>
-constexpr bool CheckedSubImpl(T x, T y, T* result) {
-  static_assert(std::is_integral<T>::value, "Type must be integral");
-  // Since the value of x+y is undefined if we have a signed type, we compute
-  // it using the unsigned type of the same size.
-  using UnsignedDst = typename std::make_unsigned<T>::type;
-  using SignedDst = typename std::make_signed<T>::type;
-  UnsignedDst ux = static_cast<UnsignedDst>(x);
-  UnsignedDst uy = static_cast<UnsignedDst>(y);
-  UnsignedDst uresult = static_cast<UnsignedDst>(ux - uy);
-  *result = static_cast<T>(uresult);
-  // Subtraction is valid if either x and y have same sign, or (x-y) and x have
-  // the same sign.
-  return (std::is_signed<T>::value)
-             ? static_cast<SignedDst>((uresult ^ ux) & (ux ^ uy)) >= 0
-             : x >= y;
-}
-
-template <typename T, typename U, class Enable = void>
-struct CheckedSubOp {};
-
-template <typename T, typename U>
-struct CheckedSubOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    // TODO(jschuh) Make this "constexpr if" once we're C++17.
-    if (CheckedSubFastOp<T, U>::is_supported)
-      return CheckedSubFastOp<T, U>::Do(x, y, result);
-
-    // Double the underlying type up to a full machine word.
-    using FastPromotion = typename FastIntegerArithmeticPromotion<T, U>::type;
-    using Promotion =
-        typename std::conditional<(IntegerBitsPlusSign<FastPromotion>::value >
-                                   IntegerBitsPlusSign<intptr_t>::value),
-                                  typename BigEnoughPromotion<T, U>::type,
-                                  FastPromotion>::type;
-    // Fail if either operand is out of range for the promoted type.
-    // TODO(jschuh): This could be made to work for a broader range of values.
-    if (BASE_NUMERICS_UNLIKELY(!IsValueInRangeForNumericType<Promotion>(x) ||
-                               !IsValueInRangeForNumericType<Promotion>(y))) {
-      return false;
-    }
-
-    Promotion presult = {};
-    bool is_valid = true;
-    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
-      presult = static_cast<Promotion>(x) - static_cast<Promotion>(y);
-    } else {
-      is_valid = CheckedSubImpl(static_cast<Promotion>(x),
-                                static_cast<Promotion>(y), &presult);
-    }
-    *result = static_cast<V>(presult);
-    return is_valid && IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-template <typename T>
-constexpr bool CheckedMulImpl(T x, T y, T* result) {
-  static_assert(std::is_integral<T>::value, "Type must be integral");
-  // Since the value of x*y is potentially undefined if we have a signed type,
-  // we compute it using the unsigned type of the same size.
-  using UnsignedDst = typename std::make_unsigned<T>::type;
-  using SignedDst = typename std::make_signed<T>::type;
-  const UnsignedDst ux = SafeUnsignedAbs(x);
-  const UnsignedDst uy = SafeUnsignedAbs(y);
-  UnsignedDst uresult = static_cast<UnsignedDst>(ux * uy);
-  const bool is_negative =
-      std::is_signed<T>::value && static_cast<SignedDst>(x ^ y) < 0;
-  *result = is_negative ? 0 - uresult : uresult;
-  // We have a fast out for unsigned identity or zero on the second operand.
-  // After that it's an unsigned overflow check on the absolute value, with
-  // a +1 bound for a negative result.
-  return uy <= UnsignedDst(!std::is_signed<T>::value || is_negative) ||
-         ux <= (std::numeric_limits<T>::max() + UnsignedDst(is_negative)) / uy;
-}
-
-template <typename T, typename U, class Enable = void>
-struct CheckedMulOp {};
-
-template <typename T, typename U>
-struct CheckedMulOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    // TODO(jschuh) Make this "constexpr if" once we're C++17.
-    if (CheckedMulFastOp<T, U>::is_supported)
-      return CheckedMulFastOp<T, U>::Do(x, y, result);
-
-    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
-    // Verify the destination type can hold the result (always true for 0).
-    if (BASE_NUMERICS_UNLIKELY((!IsValueInRangeForNumericType<Promotion>(x) ||
-                                !IsValueInRangeForNumericType<Promotion>(y)) &&
-                               x && y)) {
-      return false;
-    }
-
-    Promotion presult = {};
-    bool is_valid = true;
-    if (CheckedMulFastOp<Promotion, Promotion>::is_supported) {
-      // The fast op may be available with the promoted type.
-      is_valid = CheckedMulFastOp<Promotion, Promotion>::Do(x, y, &presult);
-    } else if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
-      presult = static_cast<Promotion>(x) * static_cast<Promotion>(y);
-    } else {
-      is_valid = CheckedMulImpl(static_cast<Promotion>(x),
-                                static_cast<Promotion>(y), &presult);
-    }
-    *result = static_cast<V>(presult);
-    return is_valid && IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-// Division just requires a check for a zero denominator or an invalid negation
-// on signed min/-1.
-template <typename T, typename U, class Enable = void>
-struct CheckedDivOp {};
-
-template <typename T, typename U>
-struct CheckedDivOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    if (BASE_NUMERICS_UNLIKELY(!y))
-      return false;
-
-    // The overflow check can be compiled away if we don't have the exact
-    // combination of types needed to trigger this case.
-    using Promotion = typename BigEnoughPromotion<T, U>::type;
-    if (BASE_NUMERICS_UNLIKELY(
-            (std::is_signed<T>::value && std::is_signed<U>::value &&
-             IsTypeInRangeForNumericType<T, Promotion>::value &&
-             static_cast<Promotion>(x) ==
-                 std::numeric_limits<Promotion>::lowest() &&
-             y == static_cast<U>(-1)))) {
-      return false;
-    }
-
-    // This branch always compiles away if the above branch wasn't removed.
-    if (BASE_NUMERICS_UNLIKELY((!IsValueInRangeForNumericType<Promotion>(x) ||
-                                !IsValueInRangeForNumericType<Promotion>(y)) &&
-                               x)) {
-      return false;
-    }
-
-    Promotion presult = Promotion(x) / Promotion(y);
-    *result = static_cast<V>(presult);
-    return IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedModOp {};
-
-template <typename T, typename U>
-struct CheckedModOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    if (BASE_NUMERICS_UNLIKELY(!y))
-      return false;
-
-    using Promotion = typename BigEnoughPromotion<T, U>::type;
-    if (BASE_NUMERICS_UNLIKELY(
-            (std::is_signed<T>::value && std::is_signed<U>::value &&
-             IsTypeInRangeForNumericType<T, Promotion>::value &&
-             static_cast<Promotion>(x) ==
-                 std::numeric_limits<Promotion>::lowest() &&
-             y == static_cast<U>(-1)))) {
-      *result = 0;
-      return true;
-    }
-
-    Promotion presult = static_cast<Promotion>(x) % static_cast<Promotion>(y);
-    *result = static_cast<Promotion>(presult);
-    return IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedLshOp {};
-
-// Left shift. Shifts less than 0 or greater than or equal to the number
-// of bits in the promoted type are undefined. Shifts of negative values
-// are undefined. Otherwise it is defined when the result fits.
-template <typename T, typename U>
-struct CheckedLshOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = T;
-  template <typename V>
-  static constexpr bool Do(T x, U shift, V* result) {
-    // Disallow negative numbers and verify the shift is in bounds.
-    if (BASE_NUMERICS_LIKELY(!IsValueNegative(x) &&
-                             as_unsigned(shift) <
-                                 as_unsigned(std::numeric_limits<T>::digits))) {
-      // Shift as unsigned to avoid undefined behavior.
-      *result = static_cast<V>(as_unsigned(x) << shift);
-      // If the shift can be reversed, we know it was valid.
-      return *result >> shift == x;
-    }
-
-    // Handle the legal corner-case of a full-width signed shift of zero.
-    return std::is_signed<T>::value && !x &&
-           as_unsigned(shift) == as_unsigned(std::numeric_limits<T>::digits);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedRshOp {};
-
-// Right shift. Shifts less than 0 or greater than or equal to the number
-// of bits in the promoted type are undefined. Otherwise, it is always defined,
-// but a right shift of a negative value is implementation-dependent.
-template <typename T, typename U>
-struct CheckedRshOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = T;
-  template <typename V>
-  static bool Do(T x, U shift, V* result) {
-    // Use the type conversion push negative values out of range.
-    if (BASE_NUMERICS_LIKELY(as_unsigned(shift) <
-                             IntegerBitsPlusSign<T>::value)) {
-      T tmp = x >> shift;
-      *result = static_cast<V>(tmp);
-      return IsValueInRangeForNumericType<V>(tmp);
-    }
-    return false;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedAndOp {};
-
-// For simplicity we support only unsigned integer results.
-template <typename T, typename U>
-struct CheckedAndOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    result_type tmp = static_cast<result_type>(x) & static_cast<result_type>(y);
-    *result = static_cast<V>(tmp);
-    return IsValueInRangeForNumericType<V>(tmp);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedOrOp {};
-
-// For simplicity we support only unsigned integers.
-template <typename T, typename U>
-struct CheckedOrOp<T,
-                   U,
-                   typename std::enable_if<std::is_integral<T>::value &&
-                                           std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    result_type tmp = static_cast<result_type>(x) | static_cast<result_type>(y);
-    *result = static_cast<V>(tmp);
-    return IsValueInRangeForNumericType<V>(tmp);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct CheckedXorOp {};
-
-// For simplicity we support only unsigned integers.
-template <typename T, typename U>
-struct CheckedXorOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    result_type tmp = static_cast<result_type>(x) ^ static_cast<result_type>(y);
-    *result = static_cast<V>(tmp);
-    return IsValueInRangeForNumericType<V>(tmp);
-  }
-};
-
-// Max doesn't really need to be implemented this way because it can't fail,
-// but it makes the code much cleaner to use the MathOp wrappers.
-template <typename T, typename U, class Enable = void>
-struct CheckedMaxOp {};
-
-template <typename T, typename U>
-struct CheckedMaxOp<
-    T,
-    U,
-    typename std::enable_if<std::is_arithmetic<T>::value &&
-                            std::is_arithmetic<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    result_type tmp = IsGreater<T, U>::Test(x, y) ? static_cast<result_type>(x)
-                                                  : static_cast<result_type>(y);
-    *result = static_cast<V>(tmp);
-    return IsValueInRangeForNumericType<V>(tmp);
-  }
-};
-
-// Min doesn't really need to be implemented this way because it can't fail,
-// but it makes the code much cleaner to use the MathOp wrappers.
-template <typename T, typename U, class Enable = void>
-struct CheckedMinOp {};
-
-template <typename T, typename U>
-struct CheckedMinOp<
-    T,
-    U,
-    typename std::enable_if<std::is_arithmetic<T>::value &&
-                            std::is_arithmetic<U>::value>::type> {
-  using result_type = typename LowestValuePromotion<T, U>::type;
-  template <typename V>
-  static constexpr bool Do(T x, U y, V* result) {
-    result_type tmp = IsLess<T, U>::Test(x, y) ? static_cast<result_type>(x)
-                                               : static_cast<result_type>(y);
-    *result = static_cast<V>(tmp);
-    return IsValueInRangeForNumericType<V>(tmp);
-  }
-};
-
-// This is just boilerplate that wraps the standard floating point arithmetic.
-// A macro isn't the nicest solution, but it beats rewriting these repeatedly.
-#define BASE_FLOAT_ARITHMETIC_OPS(NAME, OP)                              \
-  template <typename T, typename U>                                      \
-  struct Checked##NAME##Op<                                              \
-      T, U,                                                              \
-      typename std::enable_if<std::is_floating_point<T>::value ||        \
-                              std::is_floating_point<U>::value>::type> { \
-    using result_type = typename MaxExponentPromotion<T, U>::type;       \
-    template <typename V>                                                \
-    static constexpr bool Do(T x, U y, V* result) {                      \
-      using Promotion = typename MaxExponentPromotion<T, U>::type;       \
-      Promotion presult = x OP y;                                        \
-      *result = static_cast<V>(presult);                                 \
-      return IsValueInRangeForNumericType<V>(presult);                   \
-    }                                                                    \
-  };
-
-BASE_FLOAT_ARITHMETIC_OPS(Add, +)
-BASE_FLOAT_ARITHMETIC_OPS(Sub, -)
-BASE_FLOAT_ARITHMETIC_OPS(Mul, *)
-BASE_FLOAT_ARITHMETIC_OPS(Div, /)
-
-#undef BASE_FLOAT_ARITHMETIC_OPS
-
-// Floats carry around their validity state with them, but integers do not. So,
-// we wrap the underlying value in a specialization in order to hide that detail
-// and expose an interface via accessors.
-enum NumericRepresentation {
-  NUMERIC_INTEGER,
-  NUMERIC_FLOATING,
-  NUMERIC_UNKNOWN
-};
-
-template <typename NumericType>
-struct GetNumericRepresentation {
-  static const NumericRepresentation value =
-      std::is_integral<NumericType>::value
-          ? NUMERIC_INTEGER
-          : (std::is_floating_point<NumericType>::value ? NUMERIC_FLOATING
-                                                        : NUMERIC_UNKNOWN);
-};
-
-template <typename T,
-          NumericRepresentation type = GetNumericRepresentation<T>::value>
-class CheckedNumericState {};
-
-// Integrals require quite a bit of additional housekeeping to manage state.
-template <typename T>
-class CheckedNumericState<T, NUMERIC_INTEGER> {
- private:
-  // is_valid_ precedes value_ because member intializers in the constructors
-  // are evaluated in field order, and is_valid_ must be read when initializing
-  // value_.
-  bool is_valid_;
-  T value_;
-
-  // Ensures that a type conversion does not trigger undefined behavior.
-  template <typename Src>
-  static constexpr T WellDefinedConversionOrZero(const Src value,
-                                                 const bool is_valid) {
-    using SrcType = typename internal::UnderlyingType<Src>::type;
-    return (std::is_integral<SrcType>::value || is_valid)
-               ? static_cast<T>(value)
-               : static_cast<T>(0);
-  }
-
- public:
-  template <typename Src, NumericRepresentation type>
-  friend class CheckedNumericState;
-
-  constexpr CheckedNumericState() : is_valid_(true), value_(0) {}
-
-  template <typename Src>
-  constexpr CheckedNumericState(Src value, bool is_valid)
-      : is_valid_(is_valid && IsValueInRangeForNumericType<T>(value)),
-        value_(WellDefinedConversionOrZero(value, is_valid_)) {
-    static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
-  }
-
-  // Copy constructor.
-  template <typename Src>
-  constexpr CheckedNumericState(const CheckedNumericState<Src>& rhs)
-      : is_valid_(rhs.IsValid()),
-        value_(WellDefinedConversionOrZero(rhs.value(), is_valid_)) {}
-
-  template <typename Src>
-  constexpr explicit CheckedNumericState(Src value)
-      : is_valid_(IsValueInRangeForNumericType<T>(value)),
-        value_(WellDefinedConversionOrZero(value, is_valid_)) {}
-
-  constexpr bool is_valid() const { return is_valid_; }
-  constexpr T value() const { return value_; }
-};
-
-// Floating points maintain their own validity, but need translation wrappers.
-template <typename T>
-class CheckedNumericState<T, NUMERIC_FLOATING> {
- private:
-  T value_;
-
-  // Ensures that a type conversion does not trigger undefined behavior.
-  template <typename Src>
-  static constexpr T WellDefinedConversionOrNaN(const Src value,
-                                                const bool is_valid) {
-    using SrcType = typename internal::UnderlyingType<Src>::type;
-    return (StaticDstRangeRelationToSrcRange<T, SrcType>::value ==
-                NUMERIC_RANGE_CONTAINED ||
-            is_valid)
-               ? static_cast<T>(value)
-               : std::numeric_limits<T>::quiet_NaN();
-  }
-
- public:
-  template <typename Src, NumericRepresentation type>
-  friend class CheckedNumericState;
-
-  constexpr CheckedNumericState() : value_(0.0) {}
-
-  template <typename Src>
-  constexpr CheckedNumericState(Src value, bool is_valid)
-      : value_(WellDefinedConversionOrNaN(value, is_valid)) {}
-
-  template <typename Src>
-  constexpr explicit CheckedNumericState(Src value)
-      : value_(WellDefinedConversionOrNaN(
-            value,
-            IsValueInRangeForNumericType<T>(value))) {}
-
-  // Copy constructor.
-  template <typename Src>
-  constexpr CheckedNumericState(const CheckedNumericState<Src>& rhs)
-      : value_(WellDefinedConversionOrNaN(
-            rhs.value(),
-            rhs.is_valid() && IsValueInRangeForNumericType<T>(rhs.value()))) {}
-
-  constexpr bool is_valid() const {
-    // Written this way because std::isfinite is not reliably constexpr.
-    return MustTreatAsConstexpr(value_)
-               ? value_ <= std::numeric_limits<T>::max() &&
-                     value_ >= std::numeric_limits<T>::lowest()
-               : std::isfinite(value_);
-  }
-  constexpr T value() const { return value_; }
-};
-
-}  // namespace internal
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_CHECKED_MATH_IMPL_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/clamped_math.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/clamped_math.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/clamped_math.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/clamped_math.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,266 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_H_
-#define THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_H_
-
-#include <stddef.h>
-
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/clamped_math_impl.h"
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-template <typename T>
-class ClampedNumeric {
-  static_assert(std::is_arithmetic<T>::value,
-                "ClampedNumeric<T>: T must be a numeric type.");
-
- public:
-  using type = T;
-
-  constexpr ClampedNumeric() : value_(0) {}
-
-  // Copy constructor.
-  template <typename Src>
-  constexpr ClampedNumeric(const ClampedNumeric<Src>& rhs)
-      : value_(saturated_cast<T>(rhs.value_)) {}
-
-  template <typename Src>
-  friend class ClampedNumeric;
-
-  // This is not an explicit constructor because we implicitly upgrade regular
-  // numerics to ClampedNumerics to make them easier to use.
-  template <typename Src>
-  constexpr ClampedNumeric(Src value)  // NOLINT(runtime/explicit)
-      : value_(saturated_cast<T>(value)) {
-    static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
-  }
-
-  // This is not an explicit constructor because we want a seamless conversion
-  // from StrictNumeric types.
-  template <typename Src>
-  constexpr ClampedNumeric(
-      StrictNumeric<Src> value)  // NOLINT(runtime/explicit)
-      : value_(saturated_cast<T>(static_cast<Src>(value))) {}
-
-  // Returns a ClampedNumeric of the specified type, cast from the current
-  // ClampedNumeric, and saturated to the destination type.
-  template <typename Dst>
-  constexpr ClampedNumeric<typename UnderlyingType<Dst>::type> Cast() const {
-    return *this;
-  }
-
-  // Prototypes for the supported arithmetic operator overloads.
-  template <typename Src>
-  constexpr ClampedNumeric& operator+=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator-=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator*=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator/=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator%=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator<<=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator>>=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator&=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator|=(const Src rhs);
-  template <typename Src>
-  constexpr ClampedNumeric& operator^=(const Src rhs);
-
-  constexpr ClampedNumeric operator-() const {
-    // The negation of two's complement int min is int min, so that's the
-    // only overflow case where we will saturate.
-    return ClampedNumeric<T>(SaturatedNegWrapper(value_));
-  }
-
-  constexpr ClampedNumeric operator~() const {
-    return ClampedNumeric<decltype(InvertWrapper(T()))>(InvertWrapper(value_));
-  }
-
-  constexpr ClampedNumeric Abs() const {
-    // The negation of two's complement int min is int min, so that's the
-    // only overflow case where we will saturate.
-    return ClampedNumeric<T>(SaturatedAbsWrapper(value_));
-  }
-
-  template <typename U>
-  constexpr ClampedNumeric<typename MathWrapper<ClampedMaxOp, T, U>::type> Max(
-      const U rhs) const {
-    using result_type = typename MathWrapper<ClampedMaxOp, T, U>::type;
-    return ClampedNumeric<result_type>(
-        ClampedMaxOp<T, U>::Do(value_, Wrapper<U>::value(rhs)));
-  }
-
-  template <typename U>
-  constexpr ClampedNumeric<typename MathWrapper<ClampedMinOp, T, U>::type> Min(
-      const U rhs) const {
-    using result_type = typename MathWrapper<ClampedMinOp, T, U>::type;
-    return ClampedNumeric<result_type>(
-        ClampedMinOp<T, U>::Do(value_, Wrapper<U>::value(rhs)));
-  }
-
-  // This function is available only for integral types. It returns an unsigned
-  // integer of the same width as the source type, containing the absolute value
-  // of the source, and properly handling signed min.
-  constexpr ClampedNumeric<typename UnsignedOrFloatForSize<T>::type>
-  UnsignedAbs() const {
-    return ClampedNumeric<typename UnsignedOrFloatForSize<T>::type>(
-        SafeUnsignedAbs(value_));
-  }
-
-  constexpr ClampedNumeric& operator++() {
-    *this += 1;
-    return *this;
-  }
-
-  constexpr ClampedNumeric operator++(int) {
-    ClampedNumeric value = *this;
-    *this += 1;
-    return value;
-  }
-
-  constexpr ClampedNumeric& operator--() {
-    *this -= 1;
-    return *this;
-  }
-
-  constexpr ClampedNumeric operator--(int) {
-    ClampedNumeric value = *this;
-    *this -= 1;
-    return value;
-  }
-
-  // These perform the actual math operations on the ClampedNumerics.
-  // Binary arithmetic operations.
-  template <template <typename, typename, typename> class M,
-            typename L,
-            typename R>
-  static constexpr ClampedNumeric MathOp(const L lhs, const R rhs) {
-    using Math = typename MathWrapper<M, L, R>::math;
-    return ClampedNumeric<T>(
-        Math::template Do<T>(Wrapper<L>::value(lhs), Wrapper<R>::value(rhs)));
-  }
-
-  // Assignment arithmetic operations.
-  template <template <typename, typename, typename> class M, typename R>
-  constexpr ClampedNumeric& MathOp(const R rhs) {
-    using Math = typename MathWrapper<M, T, R>::math;
-    *this =
-        ClampedNumeric<T>(Math::template Do<T>(value_, Wrapper<R>::value(rhs)));
-    return *this;
-  }
-
-  template <typename Dst>
-  constexpr operator Dst() const {
-    return saturated_cast<typename ArithmeticOrUnderlyingEnum<Dst>::type>(
-        value_);
-  }
-
-  // This method extracts the raw integer value without saturating it to the
-  // destination type as the conversion operator does. This is useful when
-  // e.g. assigning to an auto type or passing as a deduced template parameter.
-  constexpr T RawValue() const { return value_; }
-
- private:
-  T value_;
-
-  // These wrappers allow us to handle state the same way for both
-  // ClampedNumeric and POD arithmetic types.
-  template <typename Src>
-  struct Wrapper {
-    static constexpr Src value(Src value) {
-      return static_cast<typename UnderlyingType<Src>::type>(value);
-    }
-  };
-};
-
-// Convience wrapper to return a new ClampedNumeric from the provided arithmetic
-// or ClampedNumericType.
-template <typename T>
-constexpr ClampedNumeric<typename UnderlyingType<T>::type> MakeClampedNum(
-    const T value) {
-  return value;
-}
-
-#if !BASE_NUMERICS_DISABLE_OSTREAM_OPERATORS
-// Overload the ostream output operator to make logging work nicely.
-template <typename T>
-std::ostream& operator<<(std::ostream& os, const ClampedNumeric<T>& value) {
-  os << static_cast<T>(value);
-  return os;
-}
-#endif
-
-// These implement the variadic wrapper for the math operations.
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R>
-constexpr ClampedNumeric<typename MathWrapper<M, L, R>::type> ClampMathOp(
-    const L lhs,
-    const R rhs) {
-  using Math = typename MathWrapper<M, L, R>::math;
-  return ClampedNumeric<typename Math::result_type>::template MathOp<M>(lhs,
-                                                                        rhs);
-}
-
-// General purpose wrapper template for arithmetic operations.
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R,
-          typename... Args>
-constexpr ClampedNumeric<typename ResultType<M, L, R, Args...>::type>
-ClampMathOp(const L lhs, const R rhs, const Args... args) {
-  return ClampMathOp<M>(ClampMathOp<M>(lhs, rhs), args...);
-}
-
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Add, +, +=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Sub, -, -=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Mul, *, *=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Div, /, /=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Mod, %, %=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Lsh, <<, <<=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Rsh, >>, >>=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, And, &, &=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Or, |, |=)
-BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Xor, ^, ^=)
-BASE_NUMERIC_ARITHMETIC_VARIADIC(Clamped, Clamp, Max)
-BASE_NUMERIC_ARITHMETIC_VARIADIC(Clamped, Clamp, Min)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLess, <)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLessOrEqual, <=)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreater, >)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreaterOrEqual, >=)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsEqual, ==)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsNotEqual, !=)
-
-}  // namespace internal
-
-using internal::ClampedNumeric;
-using internal::MakeClampedNum;
-using internal::ClampMax;
-using internal::ClampMin;
-using internal::ClampAdd;
-using internal::ClampSub;
-using internal::ClampMul;
-using internal::ClampDiv;
-using internal::ClampMod;
-using internal::ClampLsh;
-using internal::ClampRsh;
-using internal::ClampAnd;
-using internal::ClampOr;
-using internal::ClampXor;
-
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/clamped_math_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/clamped_math_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/clamped_math_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/clamped_math_impl.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,343 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_IMPL_H_
-#define THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_IMPL_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <climits>
-#include <cmath>
-#include <cstdlib>
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/checked_math.h"
-#include "third_party/base/numerics/safe_conversions.h"
-#include "third_party/base/numerics/safe_math_shared_impl.h"
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value &&
-                                  std::is_signed<T>::value>::type* = nullptr>
-constexpr T SaturatedNegWrapper(T value) {
-  return MustTreatAsConstexpr(value) || !ClampedNegFastOp<T>::is_supported
-             ? (NegateWrapper(value) != std::numeric_limits<T>::lowest()
-                    ? NegateWrapper(value)
-                    : std::numeric_limits<T>::max())
-             : ClampedNegFastOp<T>::Do(value);
-}
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value &&
-                                  !std::is_signed<T>::value>::type* = nullptr>
-constexpr T SaturatedNegWrapper(T value) {
-  return T(0);
-}
-
-template <
-    typename T,
-    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
-constexpr T SaturatedNegWrapper(T value) {
-  return -value;
-}
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
-constexpr T SaturatedAbsWrapper(T value) {
-  // The calculation below is a static identity for unsigned types, but for
-  // signed integer types it provides a non-branching, saturated absolute value.
-  // This works because SafeUnsignedAbs() returns an unsigned type, which can
-  // represent the absolute value of all negative numbers of an equal-width
-  // integer type. The call to IsValueNegative() then detects overflow in the
-  // special case of numeric_limits<T>::min(), by evaluating the bit pattern as
-  // a signed integer value. If it is the overflow case, we end up subtracting
-  // one from the unsigned result, thus saturating to numeric_limits<T>::max().
-  return static_cast<T>(SafeUnsignedAbs(value) -
-                        IsValueNegative<T>(SafeUnsignedAbs(value)));
-}
-
-template <
-    typename T,
-    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
-constexpr T SaturatedAbsWrapper(T value) {
-  return value < 0 ? -value : value;
-}
-
-template <typename T, typename U, class Enable = void>
-struct ClampedAddOp {};
-
-template <typename T, typename U>
-struct ClampedAddOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    if (ClampedAddFastOp<T, U>::is_supported)
-      return ClampedAddFastOp<T, U>::template Do<V>(x, y);
-
-    static_assert(std::is_same<V, result_type>::value ||
-                      IsTypeInRangeForNumericType<U, V>::value,
-                  "The saturation result cannot be determined from the "
-                  "provided types.");
-    const V saturated = CommonMaxOrMin<V>(IsValueNegative(y));
-    V result = {};
-    return BASE_NUMERICS_LIKELY((CheckedAddOp<T, U>::Do(x, y, &result)))
-               ? result
-               : saturated;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedSubOp {};
-
-template <typename T, typename U>
-struct ClampedSubOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    // TODO(jschuh) Make this "constexpr if" once we're C++17.
-    if (ClampedSubFastOp<T, U>::is_supported)
-      return ClampedSubFastOp<T, U>::template Do<V>(x, y);
-
-    static_assert(std::is_same<V, result_type>::value ||
-                      IsTypeInRangeForNumericType<U, V>::value,
-                  "The saturation result cannot be determined from the "
-                  "provided types.");
-    const V saturated = CommonMaxOrMin<V>(!IsValueNegative(y));
-    V result = {};
-    return BASE_NUMERICS_LIKELY((CheckedSubOp<T, U>::Do(x, y, &result)))
-               ? result
-               : saturated;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedMulOp {};
-
-template <typename T, typename U>
-struct ClampedMulOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    // TODO(jschuh) Make this "constexpr if" once we're C++17.
-    if (ClampedMulFastOp<T, U>::is_supported)
-      return ClampedMulFastOp<T, U>::template Do<V>(x, y);
-
-    V result = {};
-    const V saturated =
-        CommonMaxOrMin<V>(IsValueNegative(x) ^ IsValueNegative(y));
-    return BASE_NUMERICS_LIKELY((CheckedMulOp<T, U>::Do(x, y, &result)))
-               ? result
-               : saturated;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedDivOp {};
-
-template <typename T, typename U>
-struct ClampedDivOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    V result = {};
-    if (BASE_NUMERICS_LIKELY((CheckedDivOp<T, U>::Do(x, y, &result))))
-      return result;
-    // Saturation goes to max, min, or NaN (if x is zero).
-    return x ? CommonMaxOrMin<V>(IsValueNegative(x) ^ IsValueNegative(y))
-             : SaturationDefaultLimits<V>::NaN();
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedModOp {};
-
-template <typename T, typename U>
-struct ClampedModOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    V result = {};
-    return BASE_NUMERICS_LIKELY((CheckedModOp<T, U>::Do(x, y, &result)))
-               ? result
-               : x;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedLshOp {};
-
-// Left shift. Non-zero values saturate in the direction of the sign. A zero
-// shifted by any value always results in zero.
-template <typename T, typename U>
-struct ClampedLshOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = T;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U shift) {
-    static_assert(!std::is_signed<U>::value, "Shift value must be unsigned.");
-    if (BASE_NUMERICS_LIKELY(shift < std::numeric_limits<T>::digits)) {
-      // Shift as unsigned to avoid undefined behavior.
-      V result = static_cast<V>(as_unsigned(x) << shift);
-      // If the shift can be reversed, we know it was valid.
-      if (BASE_NUMERICS_LIKELY(result >> shift == x))
-        return result;
-    }
-    return x ? CommonMaxOrMin<V>(IsValueNegative(x)) : 0;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedRshOp {};
-
-// Right shift. Negative values saturate to -1. Positive or 0 saturates to 0.
-template <typename T, typename U>
-struct ClampedRshOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = T;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U shift) {
-    static_assert(!std::is_signed<U>::value, "Shift value must be unsigned.");
-    // Signed right shift is odd, because it saturates to -1 or 0.
-    const V saturated = as_unsigned(V(0)) - IsValueNegative(x);
-    return BASE_NUMERICS_LIKELY(shift < IntegerBitsPlusSign<T>::value)
-               ? saturated_cast<V>(x >> shift)
-               : saturated;
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedAndOp {};
-
-template <typename T, typename U>
-struct ClampedAndOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr V Do(T x, U y) {
-    return static_cast<result_type>(x) & static_cast<result_type>(y);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedOrOp {};
-
-// For simplicity we promote to unsigned integers.
-template <typename T, typename U>
-struct ClampedOrOp<T,
-                   U,
-                   typename std::enable_if<std::is_integral<T>::value &&
-                                           std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr V Do(T x, U y) {
-    return static_cast<result_type>(x) | static_cast<result_type>(y);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedXorOp {};
-
-// For simplicity we support only unsigned integers.
-template <typename T, typename U>
-struct ClampedXorOp<T,
-                    U,
-                    typename std::enable_if<std::is_integral<T>::value &&
-                                            std::is_integral<U>::value>::type> {
-  using result_type = typename std::make_unsigned<
-      typename MaxExponentPromotion<T, U>::type>::type;
-  template <typename V>
-  static constexpr V Do(T x, U y) {
-    return static_cast<result_type>(x) ^ static_cast<result_type>(y);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedMaxOp {};
-
-template <typename T, typename U>
-struct ClampedMaxOp<
-    T,
-    U,
-    typename std::enable_if<std::is_arithmetic<T>::value &&
-                            std::is_arithmetic<U>::value>::type> {
-  using result_type = typename MaxExponentPromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    return IsGreater<T, U>::Test(x, y) ? saturated_cast<V>(x)
-                                       : saturated_cast<V>(y);
-  }
-};
-
-template <typename T, typename U, class Enable = void>
-struct ClampedMinOp {};
-
-template <typename T, typename U>
-struct ClampedMinOp<
-    T,
-    U,
-    typename std::enable_if<std::is_arithmetic<T>::value &&
-                            std::is_arithmetic<U>::value>::type> {
-  using result_type = typename LowestValuePromotion<T, U>::type;
-  template <typename V = result_type>
-  static constexpr V Do(T x, U y) {
-    return IsLess<T, U>::Test(x, y) ? saturated_cast<V>(x)
-                                    : saturated_cast<V>(y);
-  }
-};
-
-// This is just boilerplate that wraps the standard floating point arithmetic.
-// A macro isn't the nicest solution, but it beats rewriting these repeatedly.
-#define BASE_FLOAT_ARITHMETIC_OPS(NAME, OP)                              \
-  template <typename T, typename U>                                      \
-  struct Clamped##NAME##Op<                                              \
-      T, U,                                                              \
-      typename std::enable_if<std::is_floating_point<T>::value ||        \
-                              std::is_floating_point<U>::value>::type> { \
-    using result_type = typename MaxExponentPromotion<T, U>::type;       \
-    template <typename V = result_type>                                  \
-    static constexpr V Do(T x, U y) {                                    \
-      return saturated_cast<V>(x OP y);                                  \
-    }                                                                    \
-  };
-
-BASE_FLOAT_ARITHMETIC_OPS(Add, +)
-BASE_FLOAT_ARITHMETIC_OPS(Sub, -)
-BASE_FLOAT_ARITHMETIC_OPS(Mul, *)
-BASE_FLOAT_ARITHMETIC_OPS(Div, /)
-
-#undef BASE_FLOAT_ARITHMETIC_OPS
-
-}  // namespace internal
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_CLAMPED_MATH_IMPL_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_conversions.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_conversions.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_conversions.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_conversions.h	2020-05-02 03:06:13.000000000 +0200
@@ -8,21 +8,18 @@
 #include <stddef.h>
 
 #include <limits>
+#include <ostream>
 #include <type_traits>
 
 #include "third_party/base/numerics/safe_conversions_impl.h"
 
-#if !defined(__native_client__) && (defined(__ARMEL__) || defined(__arch64__))
+#if defined(__ARMEL__) || defined(__arch64__)
 #include "third_party/base/numerics/safe_conversions_arm_impl.h"
 #define BASE_HAS_OPTIMIZED_SAFE_CONVERSIONS (1)
 #else
 #define BASE_HAS_OPTIMIZED_SAFE_CONVERSIONS (0)
 #endif
 
-#if !BASE_NUMERICS_DISABLE_OSTREAM_OPERATORS
-#include <ostream>
-#endif
-
 namespace pdfium {
 namespace base {
 namespace internal {
@@ -312,14 +309,12 @@
   return value;
 }
 
-#if !BASE_NUMERICS_DISABLE_OSTREAM_OPERATORS
 // Overload the ostream output operator to make logging work nicely.
 template <typename T>
 std::ostream& operator<<(std::ostream& os, const StrictNumeric<T>& value) {
   os << static_cast<T>(value);
   return os;
 }
-#endif
 
 #define BASE_NUMERIC_COMPARISON_OPERATORS(CLASS, NAME, OP)              \
   template <typename L, typename R,                                     \
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_conversions_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_conversions_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_conversions_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_conversions_impl.h	2020-05-02 03:06:13.000000000 +0200
@@ -81,9 +81,8 @@
 constexpr typename std::make_unsigned<T>::type SafeUnsignedAbs(T value) {
   static_assert(std::is_integral<T>::value, "Type must be integral");
   using UnsignedT = typename std::make_unsigned<T>::type;
-  return IsValueNegative(value)
-             ? static_cast<UnsignedT>(0u - static_cast<UnsignedT>(value))
-             : static_cast<UnsignedT>(value);
+  return IsValueNegative(value) ? 0 - static_cast<UnsignedT>(value)
+                                : static_cast<UnsignedT>(value);
 }
 
 // This allows us to switch paths on known compile-time constants.
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math.h	2020-05-02 03:06:13.000000000 +0200
@@ -1,12 +1,510 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_H_
 #define THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_H_
 
-#include "third_party/base/numerics/checked_math.h"
-#include "third_party/base/numerics/clamped_math.h"
-#include "third_party/base/numerics/safe_conversions.h"
+#include <stddef.h>
+
+#include <limits>
+#include <type_traits>
+
+#include "third_party/base/numerics/safe_math_impl.h"
+
+namespace pdfium {
+namespace base {
+namespace internal {
+
+// CheckedNumeric<> implements all the logic and operators for detecting integer
+// boundary conditions such as overflow, underflow, and invalid conversions.
+// The CheckedNumeric type implicitly converts from floating point and integer
+// data types, and contains overloads for basic arithmetic operations (i.e.: +,
+// -, *, / for all types and %, <<, >>, &, |, ^ for integers). Type promotions
+// are a slightly modified version of the standard C arithmetic rules with the
+// two differences being that there is no default promotion to int and bitwise
+// logical operations always return an unsigned of the wider type.
+//
+// You may also use one of the variadic convenience functions, which accept
+// standard arithmetic or CheckedNumeric types, perform arithmetic operations,
+// and return a CheckedNumeric result. The supported functions are:
+//  CheckAdd() - Addition.
+//  CheckSub() - Subtraction.
+//  CheckMul() - Multiplication.
+//  CheckDiv() - Division.
+//  CheckMod() - Modulous (integer only).
+//  CheckLsh() - Left integer shift (integer only).
+//  CheckRsh() - Right integer shift (integer only).
+//  CheckAnd() - Bitwise AND (integer only with unsigned result).
+//  CheckOr()  - Bitwise OR (integer only with unsigned result).
+//  CheckXor() - Bitwise XOR (integer only with unsigned result).
+//  CheckMax() - Maximum of supplied arguments.
+//  CheckMin() - Minimum of supplied arguments.
+//
+// The unary negation, increment, and decrement operators are supported, along
+// with the following unary arithmetic methods, which return a new
+// CheckedNumeric as a result of the operation:
+//  Abs() - Absolute value.
+//  UnsignedAbs() - Absolute value as an equal-width unsigned underlying type
+//          (valid for only integral types).
+//  Max() - Returns whichever is greater of the current instance or argument.
+//          The underlying return type is whichever has the greatest magnitude.
+//  Min() - Returns whichever is lowest of the current instance or argument.
+//          The underlying return type is whichever has can represent the lowest
+//          number in the smallest width (e.g. int8_t over unsigned, int over
+//          int8_t, and float over int).
+//
+// The following methods convert from CheckedNumeric to standard numeric values:
+//  AssignIfValid() - Assigns the underlying value to the supplied destination
+//          pointer if the value is currently valid and within the range
+//          supported by the destination type. Returns true on success.
+//  ****************************************************************************
+//  *  WARNING: All of the following functions return a StrictNumeric, which   *
+//  *  is valid for comparison and assignment operations, but will trigger a   *
+//  *  compile failure on attempts to assign to a type of insufficient range.  *
+//  ****************************************************************************
+//  IsValid() - Returns true if the underlying numeric value is valid (i.e. has
+//          has not wrapped and is not the result of an invalid conversion).
+//  ValueOrDie() - Returns the underlying value. If the state is not valid this
+//          call will crash on a CHECK.
+//  ValueOrDefault() - Returns the current value, or the supplied default if the
+//          state is not valid (will not trigger a CHECK).
+//
+// The following wrapper functions can be used to avoid the template
+// disambiguator syntax when converting a destination type.
+//   IsValidForType<>() in place of: a.template IsValid<Dst>()
+//   ValueOrDieForType<>() in place of: a.template ValueOrDie()
+//   ValueOrDefaultForType<>() in place of: a.template ValueOrDefault(default)
+//
+// The following are general utility methods that are useful for converting
+// between arithmetic types and CheckedNumeric types:
+//  CheckedNumeric::Cast<Dst>() - Instance method returning a CheckedNumeric
+//          derived from casting the current instance to a CheckedNumeric of
+//          the supplied destination type.
+//  MakeCheckedNum() - Creates a new CheckedNumeric from the underlying type of
+//          the supplied arithmetic, CheckedNumeric, or StrictNumeric type.
+//
+// Comparison operations are explicitly not supported because they could result
+// in a crash on an unexpected CHECK condition. You should use patterns like the
+// following for comparisons:
+//   CheckedNumeric<size_t> checked_size = untrusted_input_value;
+//   checked_size += HEADER LENGTH;
+//   if (checked_size.IsValid() && checked_size.ValueOrDie() < buffer_size)
+//     Do stuff...
+
+template <typename T>
+class CheckedNumeric {
+  static_assert(std::is_arithmetic<T>::value,
+                "CheckedNumeric<T>: T must be a numeric type.");
+
+ public:
+  using type = T;
+
+  constexpr CheckedNumeric() = default;
+
+  // Copy constructor.
+  template <typename Src>
+  constexpr CheckedNumeric(const CheckedNumeric<Src>& rhs)
+      : state_(rhs.state_.value(), rhs.IsValid()) {}
+
+  template <typename Src>
+  friend class CheckedNumeric;
+
+  // This is not an explicit constructor because we implicitly upgrade regular
+  // numerics to CheckedNumerics to make them easier to use.
+  template <typename Src>
+  constexpr CheckedNumeric(Src value)  // NOLINT(runtime/explicit)
+      : state_(value) {
+    static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
+  }
+
+  // This is not an explicit constructor because we want a seamless conversion
+  // from StrictNumeric types.
+  template <typename Src>
+  constexpr CheckedNumeric(
+      StrictNumeric<Src> value)  // NOLINT(runtime/explicit)
+      : state_(static_cast<Src>(value)) {}
+
+  // IsValid() - The public API to test if a CheckedNumeric is currently valid.
+  // A range checked destination type can be supplied using the Dst template
+  // parameter.
+  template <typename Dst = T>
+  constexpr bool IsValid() const {
+    return state_.is_valid() &&
+           IsValueInRangeForNumericType<Dst>(state_.value());
+  }
+
+  // AssignIfValid(Dst) - Assigns the underlying value if it is currently valid
+  // and is within the range supported by the destination type. Returns true if
+  // successful and false otherwise.
+  template <typename Dst>
+  constexpr bool AssignIfValid(Dst* result) const {
+    return IsValid<Dst>() ? ((*result = static_cast<Dst>(state_.value())), true)
+                          : false;
+  }
+
+  // ValueOrDie() - The primary accessor for the underlying value. If the
+  // current state is not valid it will CHECK and crash.
+  // A range checked destination type can be supplied using the Dst template
+  // parameter, which will trigger a CHECK if the value is not in bounds for
+  // the destination.
+  // The CHECK behavior can be overridden by supplying a handler as a
+  // template parameter, for test code, etc. However, the handler cannot access
+  // the underlying value, and it is not available through other means.
+  template <typename Dst = T, class CheckHandler = CheckOnFailure>
+  constexpr StrictNumeric<Dst> ValueOrDie() const {
+    return IsValid<Dst>() ? static_cast<Dst>(state_.value())
+                          : CheckHandler::template HandleFailure<Dst>();
+  }
+
+  // ValueOrDefault(T default_value) - A convenience method that returns the
+  // current value if the state is valid, and the supplied default_value for
+  // any other state.
+  // A range checked destination type can be supplied using the Dst template
+  // parameter. WARNING: This function may fail to compile or CHECK at runtime
+  // if the supplied default_value is not within range of the destination type.
+  template <typename Dst = T, typename Src>
+  constexpr StrictNumeric<Dst> ValueOrDefault(const Src default_value) const {
+    return IsValid<Dst>() ? static_cast<Dst>(state_.value())
+                          : checked_cast<Dst>(default_value);
+  }
+
+  // Returns a checked numeric of the specified type, cast from the current
+  // CheckedNumeric. If the current state is invalid or the destination cannot
+  // represent the result then the returned CheckedNumeric will be invalid.
+  template <typename Dst>
+  constexpr CheckedNumeric<typename UnderlyingType<Dst>::type> Cast() const {
+    return *this;
+  }
+
+  // This friend method is available solely for providing more detailed logging
+  // in the tests. Do not implement it in production code, because the
+  // underlying values may change at any time.
+  template <typename U>
+  friend U GetNumericValueForTest(const CheckedNumeric<U>& src);
+
+  // Prototypes for the supported arithmetic operator overloads.
+  template <typename Src>
+  CheckedNumeric& operator+=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator-=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator*=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator/=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator%=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator<<=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator>>=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator&=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator|=(const Src rhs);
+  template <typename Src>
+  CheckedNumeric& operator^=(const Src rhs);
+
+  constexpr CheckedNumeric operator-() const {
+    return CheckedNumeric<T>(
+        NegateWrapper(state_.value()),
+        IsValid() &&
+            (!std::is_signed<T>::value || std::is_floating_point<T>::value ||
+             NegateWrapper(state_.value()) !=
+                 std::numeric_limits<T>::lowest()));
+  }
+
+  constexpr CheckedNumeric operator~() const {
+    return CheckedNumeric<decltype(InvertWrapper(T()))>(
+        InvertWrapper(state_.value()), IsValid());
+  }
+
+  constexpr CheckedNumeric Abs() const {
+    return CheckedNumeric<T>(
+        AbsWrapper(state_.value()),
+        IsValid() &&
+            (!std::is_signed<T>::value || std::is_floating_point<T>::value ||
+             AbsWrapper(state_.value()) != std::numeric_limits<T>::lowest()));
+  }
+
+  template <typename U>
+  constexpr CheckedNumeric<typename MathWrapper<CheckedMaxOp, T, U>::type> Max(
+      const U rhs) const {
+    using R = typename UnderlyingType<U>::type;
+    using result_type = typename MathWrapper<CheckedMaxOp, T, U>::type;
+    // TODO(jschuh): This can be converted to the MathOp version and remain
+    // constexpr once we have C++14 support.
+    return CheckedNumeric<result_type>(
+        static_cast<result_type>(
+            IsGreater<T, R>::Test(state_.value(), Wrapper<U>::value(rhs))
+                ? state_.value()
+                : Wrapper<U>::value(rhs)),
+        state_.is_valid() && Wrapper<U>::is_valid(rhs));
+  }
+
+  template <typename U>
+  constexpr CheckedNumeric<typename MathWrapper<CheckedMinOp, T, U>::type> Min(
+      const U rhs) const {
+    using R = typename UnderlyingType<U>::type;
+    using result_type = typename MathWrapper<CheckedMinOp, T, U>::type;
+    // TODO(jschuh): This can be converted to the MathOp version and remain
+    // constexpr once we have C++14 support.
+    return CheckedNumeric<result_type>(
+        static_cast<result_type>(
+            IsLess<T, R>::Test(state_.value(), Wrapper<U>::value(rhs))
+                ? state_.value()
+                : Wrapper<U>::value(rhs)),
+        state_.is_valid() && Wrapper<U>::is_valid(rhs));
+  }
+
+  // This function is available only for integral types. It returns an unsigned
+  // integer of the same width as the source type, containing the absolute value
+  // of the source, and properly handling signed min.
+  constexpr CheckedNumeric<typename UnsignedOrFloatForSize<T>::type>
+  UnsignedAbs() const {
+    return CheckedNumeric<typename UnsignedOrFloatForSize<T>::type>(
+        SafeUnsignedAbs(state_.value()), state_.is_valid());
+  }
+
+  CheckedNumeric& operator++() {
+    *this += 1;
+    return *this;
+  }
+
+  CheckedNumeric operator++(int) {
+    CheckedNumeric value = *this;
+    *this += 1;
+    return value;
+  }
+
+  CheckedNumeric& operator--() {
+    *this -= 1;
+    return *this;
+  }
+
+  CheckedNumeric operator--(int) {
+    CheckedNumeric value = *this;
+    *this -= 1;
+    return value;
+  }
+
+  // These perform the actual math operations on the CheckedNumerics.
+  // Binary arithmetic operations.
+  template <template <typename, typename, typename> class M,
+            typename L,
+            typename R>
+  static CheckedNumeric MathOp(const L lhs, const R rhs) {
+    using Math = typename MathWrapper<M, L, R>::math;
+    T result = 0;
+    bool is_valid =
+        Wrapper<L>::is_valid(lhs) && Wrapper<R>::is_valid(rhs) &&
+        Math::Do(Wrapper<L>::value(lhs), Wrapper<R>::value(rhs), &result);
+    return CheckedNumeric<T>(result, is_valid);
+  }
+
+  // Assignment arithmetic operations.
+  template <template <typename, typename, typename> class M, typename R>
+  CheckedNumeric& MathOp(const R rhs) {
+    using Math = typename MathWrapper<M, T, R>::math;
+    T result = 0;  // Using T as the destination saves a range check.
+    bool is_valid = state_.is_valid() && Wrapper<R>::is_valid(rhs) &&
+                    Math::Do(state_.value(), Wrapper<R>::value(rhs), &result);
+    *this = CheckedNumeric<T>(result, is_valid);
+    return *this;
+  }
+
+ private:
+  CheckedNumericState<T> state_;
+
+  template <typename Src>
+  constexpr CheckedNumeric(Src value, bool is_valid)
+      : state_(value, is_valid) {}
+
+  // These wrappers allow us to handle state the same way for both
+  // CheckedNumeric and POD arithmetic types.
+  template <typename Src>
+  struct Wrapper {
+    static constexpr bool is_valid(Src) { return true; }
+    static constexpr Src value(Src value) { return value; }
+  };
+
+  template <typename Src>
+  struct Wrapper<CheckedNumeric<Src>> {
+    static constexpr bool is_valid(const CheckedNumeric<Src> v) {
+      return v.IsValid();
+    }
+    static constexpr Src value(const CheckedNumeric<Src> v) {
+      return v.state_.value();
+    }
+  };
+
+  template <typename Src>
+  struct Wrapper<StrictNumeric<Src>> {
+    static constexpr bool is_valid(const StrictNumeric<Src>) { return true; }
+    static constexpr Src value(const StrictNumeric<Src> v) {
+      return static_cast<Src>(v);
+    }
+  };
+};
+
+// Convenience functions to avoid the ugly template disambiguator syntax.
+template <typename Dst, typename Src>
+constexpr bool IsValidForType(const CheckedNumeric<Src> value) {
+  return value.template IsValid<Dst>();
+}
+
+template <typename Dst, typename Src>
+constexpr StrictNumeric<Dst> ValueOrDieForType(
+    const CheckedNumeric<Src> value) {
+  return value.template ValueOrDie<Dst>();
+}
+
+template <typename Dst, typename Src, typename Default>
+constexpr StrictNumeric<Dst> ValueOrDefaultForType(
+    const CheckedNumeric<Src> value,
+    const Default default_value) {
+  return value.template ValueOrDefault<Dst>(default_value);
+}
+
+// These variadic templates work out the return types.
+// TODO(jschuh): Rip all this out once we have C++14 non-trailing auto support.
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R,
+          typename... Args>
+struct ResultType;
+
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R>
+struct ResultType<M, L, R> {
+  using type = typename MathWrapper<M, L, R>::type;
+};
+
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R,
+          typename... Args>
+struct ResultType {
+  using type =
+      typename ResultType<M, typename ResultType<M, L, R>::type, Args...>::type;
+};
+
+// Convience wrapper to return a new CheckedNumeric from the provided arithmetic
+// or CheckedNumericType.
+template <typename T>
+constexpr CheckedNumeric<typename UnderlyingType<T>::type> MakeCheckedNum(
+    const T value) {
+  return value;
+}
+
+// These implement the variadic wrapper for the math operations.
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R>
+CheckedNumeric<typename MathWrapper<M, L, R>::type> ChkMathOp(const L lhs,
+                                                              const R rhs) {
+  using Math = typename MathWrapper<M, L, R>::math;
+  return CheckedNumeric<typename Math::result_type>::template MathOp<M>(lhs,
+                                                                        rhs);
+}
+
+// General purpose wrapper template for arithmetic operations.
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R,
+          typename... Args>
+CheckedNumeric<typename ResultType<M, L, R, Args...>::type>
+ChkMathOp(const L lhs, const R rhs, const Args... args) {
+  auto tmp = ChkMathOp<M>(lhs, rhs);
+  return tmp.IsValid() ? ChkMathOp<M>(tmp, args...)
+                       : decltype(ChkMathOp<M>(tmp, args...))(tmp);
+}
+
+// The following macros are just boilerplate for the standard arithmetic
+// operator overloads and variadic function templates. A macro isn't the nicest
+// solution, but it beats rewriting these over and over again.
+#define BASE_NUMERIC_ARITHMETIC_VARIADIC(NAME)                                \
+  template <typename L, typename R, typename... Args>                         \
+  CheckedNumeric<typename ResultType<Checked##NAME##Op, L, R, Args...>::type> \
+      Check##NAME(const L lhs, const R rhs, const Args... args) {             \
+    return ChkMathOp<Checked##NAME##Op, L, R, Args...>(lhs, rhs, args...);    \
+  }
+
+#define BASE_NUMERIC_ARITHMETIC_OPERATORS(NAME, OP, COMPOUND_OP)               \
+  /* Binary arithmetic operator for all CheckedNumeric operations. */          \
+  template <typename L, typename R,                                            \
+            typename std::enable_if<IsCheckedOp<L, R>::value>::type* =         \
+                nullptr>                                                       \
+  CheckedNumeric<typename MathWrapper<Checked##NAME##Op, L, R>::type>          \
+  operator OP(const L lhs, const R rhs) {                                      \
+    return decltype(lhs OP rhs)::template MathOp<Checked##NAME##Op>(lhs, rhs); \
+  }                                                                            \
+  /* Assignment arithmetic operator implementation from CheckedNumeric. */     \
+  template <typename L>                                                        \
+  template <typename R>                                                        \
+  CheckedNumeric<L>& CheckedNumeric<L>::operator COMPOUND_OP(const R rhs) {    \
+    return MathOp<Checked##NAME##Op>(rhs);                                     \
+  }                                                                            \
+  /* Variadic arithmetic functions that return CheckedNumeric. */              \
+  BASE_NUMERIC_ARITHMETIC_VARIADIC(NAME)
+
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Add, +, +=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Sub, -, -=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Mul, *, *=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Div, /, /=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Mod, %, %=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Lsh, <<, <<=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Rsh, >>, >>=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(And, &, &=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Or, |, |=)
+BASE_NUMERIC_ARITHMETIC_OPERATORS(Xor, ^, ^=)
+BASE_NUMERIC_ARITHMETIC_VARIADIC(Max)
+BASE_NUMERIC_ARITHMETIC_VARIADIC(Min)
+
+#undef BASE_NUMERIC_ARITHMETIC_VARIADIC
+#undef BASE_NUMERIC_ARITHMETIC_OPERATORS
+
+// These are some extra StrictNumeric operators to support simple pointer
+// arithmetic with our result types. Since wrapping on a pointer is always
+// bad, we trigger the CHECK condition here.
+template <typename L, typename R>
+L* operator+(L* lhs, const StrictNumeric<R> rhs) {
+  uintptr_t result = CheckAdd(reinterpret_cast<uintptr_t>(lhs),
+                              CheckMul(sizeof(L), static_cast<R>(rhs)))
+                         .template ValueOrDie<uintptr_t>();
+  return reinterpret_cast<L*>(result);
+}
+
+template <typename L, typename R>
+L* operator-(L* lhs, const StrictNumeric<R> rhs) {
+  uintptr_t result = CheckSub(reinterpret_cast<uintptr_t>(lhs),
+                              CheckMul(sizeof(L), static_cast<R>(rhs)))
+                         .template ValueOrDie<uintptr_t>();
+  return reinterpret_cast<L*>(result);
+}
+
+}  // namespace internal
+
+using internal::CheckedNumeric;
+using internal::IsValidForType;
+using internal::ValueOrDieForType;
+using internal::ValueOrDefaultForType;
+using internal::MakeCheckedNum;
+using internal::CheckMax;
+using internal::CheckMin;
+using internal::CheckAdd;
+using internal::CheckSub;
+using internal::CheckMul;
+using internal::CheckDiv;
+using internal::CheckMod;
+using internal::CheckLsh;
+using internal::CheckRsh;
+using internal::CheckAnd;
+using internal::CheckOr;
+using internal::CheckXor;
+
+}  // namespace base
+}  // namespace pdfium
 
 #endif  // THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_arm_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_arm_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_arm_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_arm_impl.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,124 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_ARM_IMPL_H_
-#define THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_ARM_IMPL_H_
-
-#include <cassert>
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/safe_conversions.h"
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-template <typename T, typename U>
-struct CheckedMulFastAsmOp {
-  static const bool is_supported =
-      FastIntegerArithmeticPromotion<T, U>::is_contained;
-
-  // The following is much more efficient than the Clang and GCC builtins for
-  // performing overflow-checked multiplication when a twice wider type is
-  // available. The below compiles down to 2-3 instructions, depending on the
-  // width of the types in use.
-  // As an example, an int32_t multiply compiles to:
-  //    smull   r0, r1, r0, r1
-  //    cmp     r1, r1, asr #31
-  // And an int16_t multiply compiles to:
-  //    smulbb  r1, r1, r0
-  //    asr     r2, r1, #16
-  //    cmp     r2, r1, asr #15
-  template <typename V>
-  __attribute__((always_inline)) static bool Do(T x, U y, V* result) {
-    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
-    Promotion presult;
-
-    presult = static_cast<Promotion>(x) * static_cast<Promotion>(y);
-    *result = static_cast<V>(presult);
-    return IsValueInRangeForNumericType<V>(presult);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedAddFastAsmOp {
-  static const bool is_supported =
-      BigEnoughPromotion<T, U>::is_contained &&
-      IsTypeInRangeForNumericType<
-          int32_t,
-          typename BigEnoughPromotion<T, U>::type>::value;
-
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    // This will get promoted to an int, so let the compiler do whatever is
-    // clever and rely on the saturated cast to bounds check.
-    if (IsIntegerArithmeticSafe<int, T, U>::value)
-      return saturated_cast<V>(x + y);
-
-    int32_t result;
-    int32_t x_i32 = checked_cast<int32_t>(x);
-    int32_t y_i32 = checked_cast<int32_t>(y);
-
-    asm("qadd %[result], %[first], %[second]"
-        : [result] "=r"(result)
-        : [first] "r"(x_i32), [second] "r"(y_i32));
-    return saturated_cast<V>(result);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedSubFastAsmOp {
-  static const bool is_supported =
-      BigEnoughPromotion<T, U>::is_contained &&
-      IsTypeInRangeForNumericType<
-          int32_t,
-          typename BigEnoughPromotion<T, U>::type>::value;
-
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    // This will get promoted to an int, so let the compiler do whatever is
-    // clever and rely on the saturated cast to bounds check.
-    if (IsIntegerArithmeticSafe<int, T, U>::value)
-      return saturated_cast<V>(x - y);
-
-    int32_t result;
-    int32_t x_i32 = checked_cast<int32_t>(x);
-    int32_t y_i32 = checked_cast<int32_t>(y);
-
-    asm("qsub %[result], %[first], %[second]"
-        : [result] "=r"(result)
-        : [first] "r"(x_i32), [second] "r"(y_i32));
-    return saturated_cast<V>(result);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedMulFastAsmOp {
-  static const bool is_supported = CheckedMulFastAsmOp<T, U>::is_supported;
-
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    // Use the CheckedMulFastAsmOp for full-width 32-bit values, because
-    // it's fewer instructions than promoting and then saturating.
-    if (!IsIntegerArithmeticSafe<int32_t, T, U>::value &&
-        !IsIntegerArithmeticSafe<uint32_t, T, U>::value) {
-      V result;
-      if (CheckedMulFastAsmOp<T, U>::Do(x, y, &result))
-        return result;
-      return CommonMaxOrMin<V>(IsValueNegative(x) ^ IsValueNegative(y));
-    }
-
-    assert((FastIntegerArithmeticPromotion<T, U>::is_contained));
-    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
-    return saturated_cast<V>(static_cast<Promotion>(x) *
-                             static_cast<Promotion>(y));
-  }
-};
-
-}  // namespace internal
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_ARM_IMPL_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_clang_gcc_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_clang_gcc_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_clang_gcc_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_clang_gcc_impl.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,159 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_
-#define THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_
-
-#include <cassert>
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/safe_conversions.h"
-
-#if !defined(__native_client__) && (defined(__ARMEL__) || defined(__arch64__))
-#include "third_party/base/numerics/safe_math_arm_impl.h"
-#define BASE_HAS_ASSEMBLER_SAFE_MATH (1)
-#else
-#define BASE_HAS_ASSEMBLER_SAFE_MATH (0)
-#endif
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-// These are the non-functioning boilerplate implementations of the optimized
-// safe math routines.
-#if !BASE_HAS_ASSEMBLER_SAFE_MATH
-template <typename T, typename U>
-struct CheckedMulFastAsmOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr bool Do(T, U, V*) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<bool>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedAddFastAsmOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedSubFastAsmOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedMulFastAsmOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-#endif  // BASE_HAS_ASSEMBLER_SAFE_MATH
-#undef BASE_HAS_ASSEMBLER_SAFE_MATH
-
-template <typename T, typename U>
-struct CheckedAddFastOp {
-  static const bool is_supported = true;
-  template <typename V>
-  __attribute__((always_inline)) static constexpr bool Do(T x, U y, V* result) {
-    return !__builtin_add_overflow(x, y, result);
-  }
-};
-
-template <typename T, typename U>
-struct CheckedSubFastOp {
-  static const bool is_supported = true;
-  template <typename V>
-  __attribute__((always_inline)) static constexpr bool Do(T x, U y, V* result) {
-    return !__builtin_sub_overflow(x, y, result);
-  }
-};
-
-template <typename T, typename U>
-struct CheckedMulFastOp {
-#if defined(__clang__)
-  // TODO(jschuh): Get the Clang runtime library issues sorted out so we can
-  // support full-width, mixed-sign multiply builtins.
-  // https://crbug.com/613003
-  // We can support intptr_t, uintptr_t, or a smaller common type.
-  static const bool is_supported =
-      (IsTypeInRangeForNumericType<intptr_t, T>::value &&
-       IsTypeInRangeForNumericType<intptr_t, U>::value) ||
-      (IsTypeInRangeForNumericType<uintptr_t, T>::value &&
-       IsTypeInRangeForNumericType<uintptr_t, U>::value);
-#else
-  static const bool is_supported = true;
-#endif
-  template <typename V>
-  __attribute__((always_inline)) static constexpr bool Do(T x, U y, V* result) {
-    return CheckedMulFastAsmOp<T, U>::is_supported
-               ? CheckedMulFastAsmOp<T, U>::Do(x, y, result)
-               : !__builtin_mul_overflow(x, y, result);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedAddFastOp {
-  static const bool is_supported = ClampedAddFastAsmOp<T, U>::is_supported;
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    return ClampedAddFastAsmOp<T, U>::template Do<V>(x, y);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedSubFastOp {
-  static const bool is_supported = ClampedSubFastAsmOp<T, U>::is_supported;
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    return ClampedSubFastAsmOp<T, U>::template Do<V>(x, y);
-  }
-};
-
-template <typename T, typename U>
-struct ClampedMulFastOp {
-  static const bool is_supported = ClampedMulFastAsmOp<T, U>::is_supported;
-  template <typename V>
-  __attribute__((always_inline)) static V Do(T x, U y) {
-    return ClampedMulFastAsmOp<T, U>::template Do<V>(x, y);
-  }
-};
-
-template <typename T>
-struct ClampedNegFastOp {
-  static const bool is_supported = std::is_signed<T>::value;
-  __attribute__((always_inline)) static T Do(T value) {
-    // Use this when there is no assembler path available.
-    if (!ClampedSubFastAsmOp<T, T>::is_supported) {
-      T result;
-      return !__builtin_sub_overflow(T(0), value, &result)
-                 ? result
-                 : std::numeric_limits<T>::max();
-    }
-
-    // Fallback to the normal subtraction path.
-    return ClampedSubFastOp<T, T>::template Do<T>(T(0), value);
-  }
-};
-
-}  // namespace internal
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_CLANG_GCC_IMPL_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_impl.h	1970-01-01 01:00:00.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_impl.h	2020-05-02 03:06:13.000000000 +0200
@@ -0,0 +1,647 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_IMPL_H_
+#define THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_IMPL_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <climits>
+#include <cmath>
+#include <cstdlib>
+#include <limits>
+#include <type_traits>
+
+#include "third_party/base/numerics/safe_conversions.h"
+
+namespace pdfium {
+namespace base {
+namespace internal {
+
+// Everything from here up to the floating point operations is portable C++,
+// but it may not be fast. This code could be split based on
+// platform/architecture and replaced with potentially faster implementations.
+
+// This is used for UnsignedAbs, where we need to support floating-point
+// template instantiations even though we don't actually support the operations.
+// However, there is no corresponding implementation of e.g. SafeUnsignedAbs,
+// so the float versions will not compile.
+template <typename Numeric,
+          bool IsInteger = std::is_integral<Numeric>::value,
+          bool IsFloat = std::is_floating_point<Numeric>::value>
+struct UnsignedOrFloatForSize;
+
+template <typename Numeric>
+struct UnsignedOrFloatForSize<Numeric, true, false> {
+  using type = typename std::make_unsigned<Numeric>::type;
+};
+
+template <typename Numeric>
+struct UnsignedOrFloatForSize<Numeric, false, true> {
+  using type = Numeric;
+};
+
+// Probe for builtin math overflow support on Clang and version check on GCC.
+#if defined(EMSCRIPTEN)
+// Emscripten Clang reports that it has the builtins, it may be lowered to an
+// instruction that is unsupported in asm.js
+#define USE_OVERFLOW_BUILTINS (0)
+#elif defined(__has_builtin)
+#define USE_OVERFLOW_BUILTINS (__has_builtin(__builtin_add_overflow))
+#elif defined(__GNUC__)
+#define USE_OVERFLOW_BUILTINS (__GNUC__ >= 5)
+#else
+#define USE_OVERFLOW_BUILTINS (0)
+#endif
+
+template <typename T>
+bool CheckedAddImpl(T x, T y, T* result) {
+  static_assert(std::is_integral<T>::value, "Type must be integral");
+  // Since the value of x+y is undefined if we have a signed type, we compute
+  // it using the unsigned type of the same size.
+  using UnsignedDst = typename std::make_unsigned<T>::type;
+  using SignedDst = typename std::make_signed<T>::type;
+  auto ux = static_cast<UnsignedDst>(x);
+  auto uy = static_cast<UnsignedDst>(y);
+  auto uresult = static_cast<UnsignedDst>(ux + uy);
+  *result = static_cast<T>(uresult);
+  // Addition is valid if the sign of (x + y) is equal to either that of x or
+  // that of y.
+  return (std::is_signed<T>::value)
+             ? static_cast<SignedDst>((uresult ^ ux) & (uresult ^ uy)) >= 0
+             : uresult >= uy;  // Unsigned is either valid or underflow.
+}
+
+template <typename T, typename U, class Enable = void>
+struct CheckedAddOp {};
+
+template <typename T, typename U>
+struct CheckedAddOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V>
+  static bool Do(T x, U y, V* result) {
+#if USE_OVERFLOW_BUILTINS
+    return !__builtin_add_overflow(x, y, result);
+#else
+    using Promotion = typename BigEnoughPromotion<T, U>::type;
+    Promotion presult;
+    // Fail if either operand is out of range for the promoted type.
+    // TODO(jschuh): This could be made to work for a broader range of values.
+    bool is_valid = IsValueInRangeForNumericType<Promotion>(x) &&
+                    IsValueInRangeForNumericType<Promotion>(y);
+
+    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
+      presult = static_cast<Promotion>(x) + static_cast<Promotion>(y);
+    } else {
+      is_valid &= CheckedAddImpl(static_cast<Promotion>(x),
+                                 static_cast<Promotion>(y), &presult);
+    }
+    *result = static_cast<V>(presult);
+    return is_valid && IsValueInRangeForNumericType<V>(presult);
+#endif
+  }
+};
+
+template <typename T>
+bool CheckedSubImpl(T x, T y, T* result) {
+  static_assert(std::is_integral<T>::value, "Type must be integral");
+  // Since the value of x+y is undefined if we have a signed type, we compute
+  // it using the unsigned type of the same size.
+  using UnsignedDst = typename std::make_unsigned<T>::type;
+  using SignedDst = typename std::make_signed<T>::type;
+  auto ux = static_cast<UnsignedDst>(x);
+  auto uy = static_cast<UnsignedDst>(y);
+  auto uresult = static_cast<UnsignedDst>(ux - uy);
+  *result = static_cast<T>(uresult);
+  // Subtraction is valid if either x and y have same sign, or (x-y) and x have
+  // the same sign.
+  return (std::is_signed<T>::value)
+             ? static_cast<SignedDst>((uresult ^ ux) & (ux ^ uy)) >= 0
+             : x >= y;
+}
+
+template <typename T, typename U, class Enable = void>
+struct CheckedSubOp {};
+
+template <typename T, typename U>
+struct CheckedSubOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V>
+  static bool Do(T x, U y, V* result) {
+#if USE_OVERFLOW_BUILTINS
+    return !__builtin_sub_overflow(x, y, result);
+#else
+    using Promotion = typename BigEnoughPromotion<T, U>::type;
+    Promotion presult;
+    // Fail if either operand is out of range for the promoted type.
+    // TODO(jschuh): This could be made to work for a broader range of values.
+    bool is_valid = IsValueInRangeForNumericType<Promotion>(x) &&
+                    IsValueInRangeForNumericType<Promotion>(y);
+
+    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
+      presult = static_cast<Promotion>(x) - static_cast<Promotion>(y);
+    } else {
+      is_valid &= CheckedSubImpl(static_cast<Promotion>(x),
+                                 static_cast<Promotion>(y), &presult);
+    }
+    *result = static_cast<V>(presult);
+    return is_valid && IsValueInRangeForNumericType<V>(presult);
+#endif
+  }
+};
+
+template <typename T>
+bool CheckedMulImpl(T x, T y, T* result) {
+  static_assert(std::is_integral<T>::value, "Type must be integral");
+  // Since the value of x*y is potentially undefined if we have a signed type,
+  // we compute it using the unsigned type of the same size.
+  using UnsignedDst = typename std::make_unsigned<T>::type;
+  using SignedDst = typename std::make_signed<T>::type;
+  const UnsignedDst ux = SafeUnsignedAbs(x);
+  const UnsignedDst uy = SafeUnsignedAbs(y);
+  auto uresult = static_cast<UnsignedDst>(ux * uy);
+  const bool is_negative =
+      std::is_signed<T>::value && static_cast<SignedDst>(x ^ y) < 0;
+  *result = is_negative ? 0 - uresult : uresult;
+  // We have a fast out for unsigned identity or zero on the second operand.
+  // After that it's an unsigned overflow check on the absolute value, with
+  // a +1 bound for a negative result.
+  return uy <= UnsignedDst(!std::is_signed<T>::value || is_negative) ||
+         ux <= (std::numeric_limits<T>::max() + UnsignedDst(is_negative)) / uy;
+}
+
+template <typename T, typename U, class Enable = void>
+struct CheckedMulOp {};
+
+template <typename T, typename U>
+struct CheckedMulOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V>
+  static bool Do(T x, U y, V* result) {
+#if USE_OVERFLOW_BUILTINS
+#if defined(__clang__)
+    // TODO(jschuh): Get the Clang runtime library issues sorted out so we can
+    // support full-width, mixed-sign multiply builtins.
+    // https://crbug.com/613003
+    static const bool kUseMaxInt =
+        // Narrower type than uintptr_t is always safe.
+        std::numeric_limits<__typeof__(x * y)>::digits <
+            std::numeric_limits<intptr_t>::digits ||
+        // Safe for intptr_t and uintptr_t if the sign matches.
+        (IntegerBitsPlusSign<__typeof__(x * y)>::value ==
+             IntegerBitsPlusSign<intptr_t>::value &&
+         std::is_signed<T>::value == std::is_signed<U>::value);
+#else
+    static const bool kUseMaxInt = true;
+#endif
+    if (kUseMaxInt)
+      return !__builtin_mul_overflow(x, y, result);
+#endif
+    using Promotion = typename FastIntegerArithmeticPromotion<T, U>::type;
+    Promotion presult;
+    // Fail if either operand is out of range for the promoted type.
+    // TODO(jschuh): This could be made to work for a broader range of values.
+    bool is_valid = IsValueInRangeForNumericType<Promotion>(x) &&
+                    IsValueInRangeForNumericType<Promotion>(y);
+
+    if (IsIntegerArithmeticSafe<Promotion, T, U>::value) {
+      presult = static_cast<Promotion>(x) * static_cast<Promotion>(y);
+    } else {
+      is_valid &= CheckedMulImpl(static_cast<Promotion>(x),
+                                 static_cast<Promotion>(y), &presult);
+    }
+    *result = static_cast<V>(presult);
+    return is_valid && IsValueInRangeForNumericType<V>(presult);
+  }
+};
+
+// Avoid poluting the namespace once we're done with the macro.
+#undef USE_OVERFLOW_BUILTINS
+
+// Division just requires a check for a zero denominator or an invalid negation
+// on signed min/-1.
+template <typename T>
+bool CheckedDivImpl(T x, T y, T* result) {
+  static_assert(std::is_integral<T>::value, "Type must be integral");
+  if (y && (!std::is_signed<T>::value ||
+            x != std::numeric_limits<T>::lowest() || y != static_cast<T>(-1))) {
+    *result = x / y;
+    return true;
+  }
+  return false;
+}
+
+template <typename T, typename U, class Enable = void>
+struct CheckedDivOp {};
+
+template <typename T, typename U>
+struct CheckedDivOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V>
+  static bool Do(T x, U y, V* result) {
+    using Promotion = typename BigEnoughPromotion<T, U>::type;
+    Promotion presult;
+    // Fail if either operand is out of range for the promoted type.
+    // TODO(jschuh): This could be made to work for a broader range of values.
+    bool is_valid = IsValueInRangeForNumericType<Promotion>(x) &&
+                    IsValueInRangeForNumericType<Promotion>(y);
+    is_valid &= CheckedDivImpl(static_cast<Promotion>(x),
+                               static_cast<Promotion>(y), &presult);
+    *result = static_cast<V>(presult);
+    return is_valid && IsValueInRangeForNumericType<V>(presult);
+  }
+};
+
+template <typename T>
+bool CheckedModImpl(T x, T y, T* result) {
+  static_assert(std::is_integral<T>::value, "Type must be integral");
+  if (y > 0) {
+    *result = static_cast<T>(x % y);
+    return true;
+  }
+  return false;
+}
+
+template <typename T, typename U, class Enable = void>
+struct CheckedModOp {};
+
+template <typename T, typename U>
+struct CheckedModOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V>
+  static bool Do(T x, U y, V* result) {
+    using Promotion = typename BigEnoughPromotion<T, U>::type;
+    Promotion presult;
+    bool is_valid = CheckedModImpl(static_cast<Promotion>(x),
+                                   static_cast<Promotion>(y), &presult);
+    *result = static_cast<V>(presult);
+    return is_valid && IsValueInRangeForNumericType<V>(presult);
+  }
+};
+
+template <typename T, typename U, class Enable = void>
+struct CheckedLshOp {};
+
+// Left shift. Shifts less than 0 or greater than or equal to the number
+// of bits in the promoted type are undefined. Shifts of negative values
+// are undefined. Otherwise it is defined when the result fits.
+template <typename T, typename U>
+struct CheckedLshOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = T;
+  template <typename V>
+  static bool Do(T x, U shift, V* result) {
+    using ShiftType = typename std::make_unsigned<T>::type;
+    static const ShiftType kBitWidth = IntegerBitsPlusSign<T>::value;
+    const auto real_shift = static_cast<ShiftType>(shift);
+    // Signed shift is not legal on negative values.
+    if (!IsValueNegative(x) && real_shift < kBitWidth) {
+      // Just use a multiplication because it's easy.
+      // TODO(jschuh): This could probably be made more efficient.
+      if (!std::is_signed<T>::value || real_shift != kBitWidth - 1)
+        return CheckedMulOp<T, T>::Do(x, static_cast<T>(1) << shift, result);
+      return !x;  // Special case zero for a full width signed shift.
+    }
+    return false;
+  }
+};
+
+template <typename T, typename U, class Enable = void>
+struct CheckedRshOp {};
+
+// Right shift. Shifts less than 0 or greater than or equal to the number
+// of bits in the promoted type are undefined. Otherwise, it is always defined,
+// but a right shift of a negative value is implementation-dependent.
+template <typename T, typename U>
+struct CheckedRshOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = T;
+  template <typename V = result_type>
+  static bool Do(T x, U shift, V* result) {
+    // Use the type conversion push negative values out of range.
+    using ShiftType = typename std::make_unsigned<T>::type;
+    if (static_cast<ShiftType>(shift) < IntegerBitsPlusSign<T>::value) {
+      T tmp = x >> shift;
+      *result = static_cast<V>(tmp);
+      return IsValueInRangeForNumericType<V>(tmp);
+    }
+    return false;
+  }
+};
+
+template <typename T, typename U, class Enable = void>
+struct CheckedAndOp {};
+
+// For simplicity we support only unsigned integer results.
+template <typename T, typename U>
+struct CheckedAndOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename std::make_unsigned<
+      typename MaxExponentPromotion<T, U>::type>::type;
+  template <typename V = result_type>
+  static bool Do(T x, U y, V* result) {
+    result_type tmp = static_cast<result_type>(x) & static_cast<result_type>(y);
+    *result = static_cast<V>(tmp);
+    return IsValueInRangeForNumericType<V>(tmp);
+  }
+};
+
+template <typename T, typename U, class Enable = void>
+struct CheckedOrOp {};
+
+// For simplicity we support only unsigned integers.
+template <typename T, typename U>
+struct CheckedOrOp<T,
+                   U,
+                   typename std::enable_if<std::is_integral<T>::value &&
+                                           std::is_integral<U>::value>::type> {
+  using result_type = typename std::make_unsigned<
+      typename MaxExponentPromotion<T, U>::type>::type;
+  template <typename V = result_type>
+  static bool Do(T x, U y, V* result) {
+    result_type tmp = static_cast<result_type>(x) | static_cast<result_type>(y);
+    *result = static_cast<V>(tmp);
+    return IsValueInRangeForNumericType<V>(tmp);
+  }
+};
+
+template <typename T, typename U, class Enable = void>
+struct CheckedXorOp {};
+
+// For simplicity we support only unsigned integers.
+template <typename T, typename U>
+struct CheckedXorOp<T,
+                    U,
+                    typename std::enable_if<std::is_integral<T>::value &&
+                                            std::is_integral<U>::value>::type> {
+  using result_type = typename std::make_unsigned<
+      typename MaxExponentPromotion<T, U>::type>::type;
+  template <typename V = result_type>
+  static bool Do(T x, U y, V* result) {
+    result_type tmp = static_cast<result_type>(x) ^ static_cast<result_type>(y);
+    *result = static_cast<V>(tmp);
+    return IsValueInRangeForNumericType<V>(tmp);
+  }
+};
+
+// Max doesn't really need to be implemented this way because it can't fail,
+// but it makes the code much cleaner to use the MathOp wrappers.
+template <typename T, typename U, class Enable = void>
+struct CheckedMaxOp {};
+
+template <typename T, typename U>
+struct CheckedMaxOp<
+    T,
+    U,
+    typename std::enable_if<std::is_arithmetic<T>::value &&
+                            std::is_arithmetic<U>::value>::type> {
+  using result_type = typename MaxExponentPromotion<T, U>::type;
+  template <typename V = result_type>
+  static bool Do(T x, U y, V* result) {
+    *result = IsGreater<T, U>::Test(x, y) ? static_cast<result_type>(x)
+                                          : static_cast<result_type>(y);
+    return true;
+  }
+};
+
+// Min doesn't really need to be implemented this way because it can't fail,
+// but it makes the code much cleaner to use the MathOp wrappers.
+template <typename T, typename U, class Enable = void>
+struct CheckedMinOp {};
+
+template <typename T, typename U>
+struct CheckedMinOp<
+    T,
+    U,
+    typename std::enable_if<std::is_arithmetic<T>::value &&
+                            std::is_arithmetic<U>::value>::type> {
+  using result_type = typename LowestValuePromotion<T, U>::type;
+  template <typename V = result_type>
+  static bool Do(T x, U y, V* result) {
+    *result = IsLess<T, U>::Test(x, y) ? static_cast<result_type>(x)
+                                       : static_cast<result_type>(y);
+    return true;
+  }
+};
+
+// This is just boilerplate that wraps the standard floating point arithmetic.
+// A macro isn't the nicest solution, but it beats rewriting these repeatedly.
+#define BASE_FLOAT_ARITHMETIC_OPS(NAME, OP)                                    \
+  template <typename T, typename U>                                            \
+  struct Checked##NAME##Op<                                                    \
+      T, U, typename std::enable_if<std::is_floating_point<T>::value ||        \
+                                    std::is_floating_point<U>::value>::type> { \
+    using result_type = typename MaxExponentPromotion<T, U>::type;             \
+    template <typename V>                                                      \
+    static bool Do(T x, U y, V* result) {                                      \
+      using Promotion = typename MaxExponentPromotion<T, U>::type;             \
+      Promotion presult = x OP y;                                              \
+      *result = static_cast<V>(presult);                                       \
+      return IsValueInRangeForNumericType<V>(presult);                         \
+    }                                                                          \
+  };
+
+BASE_FLOAT_ARITHMETIC_OPS(Add, +)
+BASE_FLOAT_ARITHMETIC_OPS(Sub, -)
+BASE_FLOAT_ARITHMETIC_OPS(Mul, *)
+BASE_FLOAT_ARITHMETIC_OPS(Div, /)
+
+#undef BASE_FLOAT_ARITHMETIC_OPS
+
+// Wrap the unary operations to allow SFINAE when instantiating integrals versus
+// floating points. These don't perform any overflow checking. Rather, they
+// exhibit well-defined overflow semantics and rely on the caller to detect
+// if an overflow occured.
+
+template <typename T,
+          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
+constexpr T NegateWrapper(T value) {
+  using UnsignedT = typename std::make_unsigned<T>::type;
+  // This will compile to a NEG on Intel, and is normal negation on ARM.
+  return static_cast<T>(UnsignedT(0) - static_cast<UnsignedT>(value));
+}
+
+template <
+    typename T,
+    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
+constexpr T NegateWrapper(T value) {
+  return -value;
+}
+
+template <typename T,
+          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
+constexpr typename std::make_unsigned<T>::type InvertWrapper(T value) {
+  return ~value;
+}
+
+template <typename T,
+          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
+constexpr T AbsWrapper(T value) {
+  return static_cast<T>(SafeUnsignedAbs(value));
+}
+
+template <
+    typename T,
+    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
+constexpr T AbsWrapper(T value) {
+  return value < 0 ? -value : value;
+}
+
+// Floats carry around their validity state with them, but integers do not. So,
+// we wrap the underlying value in a specialization in order to hide that detail
+// and expose an interface via accessors.
+enum NumericRepresentation {
+  NUMERIC_INTEGER,
+  NUMERIC_FLOATING,
+  NUMERIC_UNKNOWN
+};
+
+template <typename NumericType>
+struct GetNumericRepresentation {
+  static const NumericRepresentation value =
+      std::is_integral<NumericType>::value
+          ? NUMERIC_INTEGER
+          : (std::is_floating_point<NumericType>::value ? NUMERIC_FLOATING
+                                                        : NUMERIC_UNKNOWN);
+};
+
+template <typename T, NumericRepresentation type =
+                          GetNumericRepresentation<T>::value>
+class CheckedNumericState {};
+
+// Integrals require quite a bit of additional housekeeping to manage state.
+template <typename T>
+class CheckedNumericState<T, NUMERIC_INTEGER> {
+ private:
+  // is_valid_ precedes value_ because member intializers in the constructors
+  // are evaluated in field order, and is_valid_ must be read when initializing
+  // value_.
+  bool is_valid_;
+  T value_;
+
+  // Ensures that a type conversion does not trigger undefined behavior.
+  template <typename Src>
+  static constexpr T WellDefinedConversionOrZero(const Src value,
+                                                 const bool is_valid) {
+    using SrcType = typename internal::UnderlyingType<Src>::type;
+    return (std::is_integral<SrcType>::value || is_valid)
+               ? static_cast<T>(value)
+               : static_cast<T>(0);
+  }
+
+ public:
+  template <typename Src, NumericRepresentation type>
+  friend class CheckedNumericState;
+
+  constexpr CheckedNumericState() : is_valid_(true), value_(0) {}
+
+  template <typename Src>
+  constexpr CheckedNumericState(Src value, bool is_valid)
+      : is_valid_(is_valid && IsValueInRangeForNumericType<T>(value)),
+        value_(WellDefinedConversionOrZero(value, is_valid_)) {
+    static_assert(std::is_arithmetic<Src>::value, "Argument must be numeric.");
+  }
+
+  // Copy constructor.
+  template <typename Src>
+  constexpr CheckedNumericState(const CheckedNumericState<Src>& rhs)
+      : is_valid_(rhs.IsValid()),
+        value_(WellDefinedConversionOrZero(rhs.value(), is_valid_)) {}
+
+  template <typename Src>
+  constexpr explicit CheckedNumericState(Src value)
+      : is_valid_(IsValueInRangeForNumericType<T>(value)),
+        value_(WellDefinedConversionOrZero(value, is_valid_)) {}
+
+  constexpr bool is_valid() const { return is_valid_; }
+  constexpr T value() const { return value_; }
+};
+
+// Floating points maintain their own validity, but need translation wrappers.
+template <typename T>
+class CheckedNumericState<T, NUMERIC_FLOATING> {
+ private:
+  T value_;
+
+  // Ensures that a type conversion does not trigger undefined behavior.
+  template <typename Src>
+  static constexpr T WellDefinedConversionOrNaN(const Src value,
+                                                const bool is_valid) {
+    using SrcType = typename internal::UnderlyingType<Src>::type;
+    return (StaticDstRangeRelationToSrcRange<T, SrcType>::value ==
+                NUMERIC_RANGE_CONTAINED ||
+            is_valid)
+               ? static_cast<T>(value)
+               : std::numeric_limits<T>::quiet_NaN();
+  }
+
+ public:
+  template <typename Src, NumericRepresentation type>
+  friend class CheckedNumericState;
+
+  constexpr CheckedNumericState() : value_(0.0) {}
+
+  template <typename Src>
+  constexpr CheckedNumericState(Src value, bool is_valid)
+      : value_(WellDefinedConversionOrNaN(value, is_valid)) {}
+
+  template <typename Src>
+  constexpr explicit CheckedNumericState(Src value)
+      : value_(WellDefinedConversionOrNaN(
+            value,
+            IsValueInRangeForNumericType<T>(value))) {}
+
+  // Copy constructor.
+  template <typename Src>
+  constexpr CheckedNumericState(const CheckedNumericState<Src>& rhs)
+      : value_(WellDefinedConversionOrNaN(
+            rhs.value(),
+            rhs.is_valid() && IsValueInRangeForNumericType<T>(rhs.value()))) {}
+
+  constexpr bool is_valid() const {
+    // Written this way because std::isfinite is not reliably constexpr.
+    // TODO(jschuh): Fix this if the libraries ever get fixed.
+    return value_ <= std::numeric_limits<T>::max() &&
+           value_ >= std::numeric_limits<T>::lowest();
+  }
+  constexpr T value() const { return value_; }
+};
+
+template <template <typename, typename, typename> class M,
+          typename L,
+          typename R>
+struct MathWrapper {
+  using math = M<typename UnderlyingType<L>::type,
+                 typename UnderlyingType<R>::type,
+                 void>;
+  using type = typename math::result_type;
+};
+
+}  // namespace internal
+}  // namespace base
+}  // namespace pdfium
+
+#endif  // THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_IMPL_H_
diff -Naur workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_shared_impl.h workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_shared_impl.h
--- workdir/UnpackedTarball/pdfium/third_party/base/numerics/safe_math_shared_impl.h	2020-10-26 19:26:04.000000000 +0100
+++ workdir/UnpackedTarball/pdfium.4137/third_party/base/numerics/safe_math_shared_impl.h	1970-01-01 01:00:00.000000000 +0100
@@ -1,242 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_SHARED_IMPL_H_
-#define THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_SHARED_IMPL_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <cassert>
-#include <climits>
-#include <cmath>
-#include <cstdlib>
-#include <limits>
-#include <type_traits>
-
-#include "third_party/base/numerics/safe_conversions.h"
-
-#ifdef __asmjs__
-// Optimized safe math instructions are incompatible with asmjs.
-#define BASE_HAS_OPTIMIZED_SAFE_MATH (0)
-// Where available use builtin math overflow support on Clang and GCC.
-#elif !defined(__native_client__) &&                         \
-      ((defined(__clang__) &&                                \
-        ((__clang_major__ > 3) ||                            \
-         (__clang_major__ == 3 && __clang_minor__ >= 4))) || \
-       (defined(__GNUC__) && __GNUC__ >= 5))
-#include "third_party/base/numerics/safe_math_clang_gcc_impl.h"
-#define BASE_HAS_OPTIMIZED_SAFE_MATH (1)
-#else
-#define BASE_HAS_OPTIMIZED_SAFE_MATH (0)
-#endif
-
-namespace pdfium {
-namespace base {
-namespace internal {
-
-// These are the non-functioning boilerplate implementations of the optimized
-// safe math routines.
-#if !BASE_HAS_OPTIMIZED_SAFE_MATH
-template <typename T, typename U>
-struct CheckedAddFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr bool Do(T, U, V*) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<bool>();
-  }
-};
-
-template <typename T, typename U>
-struct CheckedSubFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr bool Do(T, U, V*) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<bool>();
-  }
-};
-
-template <typename T, typename U>
-struct CheckedMulFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr bool Do(T, U, V*) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<bool>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedAddFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedSubFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-
-template <typename T, typename U>
-struct ClampedMulFastOp {
-  static const bool is_supported = false;
-  template <typename V>
-  static constexpr V Do(T, U) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<V>();
-  }
-};
-
-template <typename T>
-struct ClampedNegFastOp {
-  static const bool is_supported = false;
-  static constexpr T Do(T) {
-    // Force a compile failure if instantiated.
-    return CheckOnFailure::template HandleFailure<T>();
-  }
-};
-#endif  // BASE_HAS_OPTIMIZED_SAFE_MATH
-#undef BASE_HAS_OPTIMIZED_SAFE_MATH
-
-// This is used for UnsignedAbs, where we need to support floating-point
-// template instantiations even though we don't actually support the operations.
-// However, there is no corresponding implementation of e.g. SafeUnsignedAbs,
-// so the float versions will not compile.
-template <typename Numeric,
-          bool IsInteger = std::is_integral<Numeric>::value,
-          bool IsFloat = std::is_floating_point<Numeric>::value>
-struct UnsignedOrFloatForSize;
-
-template <typename Numeric>
-struct UnsignedOrFloatForSize<Numeric, true, false> {
-  using type = typename std::make_unsigned<Numeric>::type;
-};
-
-template <typename Numeric>
-struct UnsignedOrFloatForSize<Numeric, false, true> {
-  using type = Numeric;
-};
-
-// Wrap the unary operations to allow SFINAE when instantiating integrals versus
-// floating points. These don't perform any overflow checking. Rather, they
-// exhibit well-defined overflow semantics and rely on the caller to detect
-// if an overflow occured.
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
-constexpr T NegateWrapper(T value) {
-  using UnsignedT = typename std::make_unsigned<T>::type;
-  // This will compile to a NEG on Intel, and is normal negation on ARM.
-  return static_cast<T>(UnsignedT(0) - static_cast<UnsignedT>(value));
-}
-
-template <
-    typename T,
-    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
-constexpr T NegateWrapper(T value) {
-  return -value;
-}
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
-constexpr typename std::make_unsigned<T>::type InvertWrapper(T value) {
-  return ~value;
-}
-
-template <typename T,
-          typename std::enable_if<std::is_integral<T>::value>::type* = nullptr>
-constexpr T AbsWrapper(T value) {
-  return static_cast<T>(SafeUnsignedAbs(value));
-}
-
-template <
-    typename T,
-    typename std::enable_if<std::is_floating_point<T>::value>::type* = nullptr>
-constexpr T AbsWrapper(T value) {
-  return value < 0 ? -value : value;
-}
-
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R>
-struct MathWrapper {
-  using math = M<typename UnderlyingType<L>::type,
-                 typename UnderlyingType<R>::type,
-                 void>;
-  using type = typename math::result_type;
-};
-
-// These variadic templates work out the return types.
-// TODO(jschuh): Rip all this out once we have C++14 non-trailing auto support.
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R,
-          typename... Args>
-struct ResultType;
-
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R>
-struct ResultType<M, L, R> {
-  using type = typename MathWrapper<M, L, R>::type;
-};
-
-template <template <typename, typename, typename> class M,
-          typename L,
-          typename R,
-          typename... Args>
-struct ResultType {
-  using type =
-      typename ResultType<M, typename ResultType<M, L, R>::type, Args...>::type;
-};
-
-// The following macros are just boilerplate for the standard arithmetic
-// operator overloads and variadic function templates. A macro isn't the nicest
-// solution, but it beats rewriting these over and over again.
-#define BASE_NUMERIC_ARITHMETIC_VARIADIC(CLASS, CL_ABBR, OP_NAME)       \
-  template <typename L, typename R, typename... Args>                   \
-  constexpr CLASS##Numeric<                                             \
-      typename ResultType<CLASS##OP_NAME##Op, L, R, Args...>::type>     \
-      CL_ABBR##OP_NAME(const L lhs, const R rhs, const Args... args) {  \
-    return CL_ABBR##MathOp<CLASS##OP_NAME##Op, L, R, Args...>(lhs, rhs, \
-                                                              args...); \
-  }
-
-#define BASE_NUMERIC_ARITHMETIC_OPERATORS(CLASS, CL_ABBR, OP_NAME, OP, CMP_OP) \
-  /* Binary arithmetic operator for all CLASS##Numeric operations. */          \
-  template <typename L, typename R,                                            \
-            typename std::enable_if<Is##CLASS##Op<L, R>::value>::type* =       \
-                nullptr>                                                       \
-  constexpr CLASS##Numeric<                                                    \
-      typename MathWrapper<CLASS##OP_NAME##Op, L, R>::type>                    \
-  operator OP(const L lhs, const R rhs) {                                      \
-    return decltype(lhs OP rhs)::template MathOp<CLASS##OP_NAME##Op>(lhs,      \
-                                                                     rhs);     \
-  }                                                                            \
-  /* Assignment arithmetic operator implementation from CLASS##Numeric. */     \
-  template <typename L>                                                        \
-  template <typename R>                                                        \
-  constexpr CLASS##Numeric<L>& CLASS##Numeric<L>::operator CMP_OP(             \
-      const R rhs) {                                                           \
-    return MathOp<CLASS##OP_NAME##Op>(rhs);                                    \
-  }                                                                            \
-  /* Variadic arithmetic functions that return CLASS##Numeric. */              \
-  BASE_NUMERIC_ARITHMETIC_VARIADIC(CLASS, CL_ABBR, OP_NAME)
-
-}  // namespace internal
-}  // namespace base
-}  // namespace pdfium
-
-#endif  // THIRD_PARTY_BASE_NUMERICS_SAFE_MATH_SHARED_IMPL_H_