Revert of components/metrics: Add runtime memory leak detector

components/metrics/leak_detector/custom_allocator.cc

-// Copyright 2015 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.
-
-#include "components/metrics/leak_detector/custom_allocator.h"
-
-#include <stddef.h>
-
-namespace metrics {
-namespace leak_detector {
-
-namespace {
-
-// Wrappers around new and delete.
-void* DefaultAlloc(size_t size) {
-  return new char[size];
-}
-void DefaultFree(void* ptr, size_t /* size */) {
-  delete[] reinterpret_cast<char*>(ptr);
-}
-
-CustomAllocator::AllocFunc g_alloc_func = nullptr;
-CustomAllocator::FreeFunc g_free_func = nullptr;
-
-}  // namespace
-
-// static
-void CustomAllocator::Initialize() {
-  Initialize(&DefaultAlloc, &DefaultFree);
-}
-
-// static
-void CustomAllocator::Initialize(AllocFunc alloc_func, FreeFunc free_func) {
-  g_alloc_func = alloc_func;
-  g_free_func = free_func;
-}
-
-// static
-bool CustomAllocator::Shutdown() {
-  g_alloc_func = nullptr;
-  g_free_func = nullptr;
-  return true;
-}
-
-// static
-bool CustomAllocator::IsInitialized() {
-  return g_alloc_func && g_free_func;
-}
-
-// static
-void* CustomAllocator::Allocate(size_t size) {
-  return g_alloc_func(size);
-}
-
-// static
-void CustomAllocator::Free(void* ptr, size_t size) {
-  g_free_func(ptr, size);
-}
-
-}  // namespace leak_detector
-}  // namespace metrics