Revert of components/metrics: Add runtime memory leak detector

components/metrics/leak_detector/call_stack_table.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/call_stack_table.h"
-
-#include "components/metrics/leak_detector/call_stack_manager.h"
-
-namespace metrics {
-namespace leak_detector {
-
-namespace {
-
-using ValueType = LeakDetectorValueType;
-
-// During leak analysis, we only want to examine the top
-// |kMaxCountOfSuspciousStacks| entries.
-const int kMaxCountOfSuspciousStacks = 16;
-
-const int kInitialHashTableSize = 1999;
-
-}  // namespace
-
-size_t CallStackTable::StoredHash::operator()(
-    const CallStack* call_stack) const {
-  // The call stack object should already have a hash computed when it was
-  // created.
-  //
-  // This is NOT the actual hash computation function for a new call stack.
-  return call_stack->hash;
-}
-
-CallStackTable::CallStackTable(int call_stack_suspicion_threshold)
-    : num_allocs_(0),
-      num_frees_(0),
-      entry_map_(kInitialHashTableSize),
-      leak_analyzer_(kMaxCountOfSuspciousStacks,
-                     call_stack_suspicion_threshold) {}
-
-CallStackTable::~CallStackTable() {}
-
-void CallStackTable::Add(const CallStack* call_stack) {
-  Entry* entry = &entry_map_[call_stack];
-
-  ++entry->net_num_allocs;
-  ++num_allocs_;
-}
-
-void CallStackTable::Remove(const CallStack* call_stack) {
-  auto iter = entry_map_.find(call_stack);
-  if (iter == entry_map_.end())
-    return;
-  Entry* entry = &iter->second;
-  --entry->net_num_allocs;
-  ++num_frees_;
-
-  // Delete zero-alloc entries to free up space.
-  if (entry->net_num_allocs == 0)
-    entry_map_.erase(iter);
-}
-
-void CallStackTable::TestForLeaks() {
-  // Add all entries to the ranked list.
-  RankedList ranked_list(kMaxCountOfSuspciousStacks);
-
-  for (const auto& entry_pair : entry_map_) {
-    const Entry& entry = entry_pair.second;
-    // Assumes that |entry.net_num_allocs| is always > 0. If that changes
-    // elsewhere in this class, this code should be updated to only pass values
-    // > 0 to |ranked_list|.
-    LeakDetectorValueType call_stack_value(entry_pair.first);
-    ranked_list.Add(call_stack_value, entry.net_num_allocs);
-  }
-  leak_analyzer_.AddSample(ranked_list.Pass());
-}
-
-}  // namespace leak_detector
-}  // namespace metrics