Revert of components/metrics: Add runtime memory leak detector

components/metrics/leak_detector/ranked_list.h

-// 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.
-
-#ifndef COMPONENTS_METRICS_LEAK_DETECTOR_RANKED_LIST_H_
-#define COMPONENTS_METRICS_LEAK_DETECTOR_RANKED_LIST_H_
-
-#include <stddef.h>
-
-#include <list>
-
-#include "base/macros.h"
-#include "base/move.h"
-#include "components/metrics/leak_detector/custom_allocator.h"
-#include "components/metrics/leak_detector/leak_detector_value_type.h"
-#include "components/metrics/leak_detector/stl_allocator.h"
-
-namespace metrics {
-namespace leak_detector {
-
-// RankedList lets you add entries consisting of a value-count pair, and
-// automatically sorts them internally by count in descending order. This allows
-// for the user of this list to put value-count pairs into this list without
-// having to explicitly sort them by count.
-class RankedList {
-  MOVE_ONLY_TYPE_FOR_CPP_03(RankedList, RValue);
-
- public:
-  using ValueType = LeakDetectorValueType;
-
-  // A single entry in the RankedList. The RankedList sorts entries by |count|
-  // in descending order.
-  struct Entry {
-    ValueType value;
-    int count;
-
-    // Create a < comparator for reverse sorting.
-    bool operator<(const Entry& entry) const { return count > entry.count; }
-  };
-
-  using EntryList = std::list<Entry, STLAllocator<Entry, CustomAllocator>>;
-  using const_iterator = EntryList::const_iterator;
-
-  explicit RankedList(size_t max_size);
-  ~RankedList();
-
-  // For move semantics.
-  RankedList(RValue other);
-  RankedList& operator=(RValue other);
-
-  // Accessors for begin() and end() const iterators.
-  const_iterator begin() const { return entries_.begin(); }
-  const_iterator end() const { return entries_.end(); }
-
-  size_t size() const { return entries_.size(); }
-  size_t max_size() const { return max_size_; }
-
-  // Add a new value-count pair to the list. Does not check for existing entries
-  // with the same value. Is an O(n) operation due to ordering.
-  void Add(const ValueType& value, int count);
-
- private:
-  // Max and min counts. Returns 0 if the list is empty.
-  int max_count() const {
-    return entries_.empty() ? 0 : entries_.begin()->count;
-  }
-  int min_count() const {
-    return entries_.empty() ? 0 : entries_.rbegin()->count;
-  }
-
-  // Max number of items that can be stored in the list.
-  size_t max_size_;
-
-  // Points to the array of entries.
-  std::list<Entry, STLAllocator<Entry, CustomAllocator>> entries_;
-};
-
-}  // namespace leak_detector
-}  // namespace metrics
-
-#endif  // COMPONENTS_METRICS_LEAK_DETECTOR_RANKED_LIST_H_