Move histogram_manager from components/metrics to components/cronet

components/metrics/histogram_manager.h

-// 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 COMPONENTS_METRICS_HISTOGRAM_MANAGER_H_
-#define COMPONENTS_METRICS_HISTOGRAM_MANAGER_H_
-
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/lazy_instance.h"
-#include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram_flattener.h"
-#include "base/metrics/histogram_snapshot_manager.h"
-#include "components/metrics/proto/chrome_user_metrics_extension.pb.h"
-
-namespace metrics {
-
-// TODO(mef): crbug.com/441441. Move components/metrics/histogram_manager.*
-// files into components/android/cronet.
-//
-// A HistogramManager instance is created by Android.  It is the central
-// controller for the acquisition of log data, and the automatic transmission of
-// that log data to an external server.
-class HistogramManager : public base::HistogramFlattener {
- public:
-  HistogramManager();
-  ~HistogramManager() override;
-
-  // Snapshot all histograms to record the delta into |uma_proto_| and then
-  // returns the serialized protobuf representation of the record in |data|.
-  // Returns true if it was successfully serialized.
-  bool GetDeltas(std::vector<uint8>* data);
-
-  // TODO(mef): Hang Histogram Manager off java object instead of singleton.
-  static HistogramManager* GetInstance();
-
- private:
-  friend struct base::DefaultLazyInstanceTraits<HistogramManager>;
-
-  // base::HistogramFlattener:
-  void RecordDelta(const base::HistogramBase& histogram,
-                   const base::HistogramSamples& snapshot) override;
-  void InconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) override;
-  void UniqueInconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) override;
-  void InconsistencyDetectedInLoggedCount(int amount) override;
-
-  base::HistogramSnapshotManager histogram_snapshot_manager_;
-
-  // Stores the protocol buffer representation for this log.
-  metrics::ChromeUserMetricsExtension uma_proto_;
-
-  DISALLOW_COPY_AND_ASSIGN(HistogramManager);
-};
-
-}  // namespace metrics
-
-#endif  // COMPONENTS_METRICS_HISTOGRAM_MANAGER_H_