Disk cache: Remove stats_histogram.

net/disk_cache/blockfile/stats_histogram.h

-// Copyright (c) 2012 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 NET_DISK_CACHE_BLOCKFILE_STATS_HISTOGRAM_H_
-#define NET_DISK_CACHE_BLOCKFILE_STATS_HISTOGRAM_H_
-
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram.h"
-
-namespace base {
-class BucketRanges;
-class HistogramSamples;
-class SampleVector;
-}  // namespace base
-
-namespace disk_cache {
-
-class Stats;
-
-// This class provides support for sending the disk cache size stats as a UMA
-// histogram. We'll provide our own storage and management for the data, and a
-// SampleVector with a copy of our data.
-//
-// Class derivation of Histogram "deprecated," and should not be copied, and
-// may eventually go away.
-//
-class StatsHistogram : public base::Histogram {
- public:
-  StatsHistogram(const std::string& name,
-                 Sample minimum,
-                 Sample maximum,
-                 const base::BucketRanges* ranges,
-                 const Stats* stats);
-  virtual ~StatsHistogram();
-
-  static void InitializeBucketRanges(const Stats* stats,
-                                     base::BucketRanges* ranges);
-  static StatsHistogram* FactoryGet(const std::string& name,
-                                    const Stats* stats);
-
-  // Disables this histogram when the underlying Stats go away.
-  void Disable();
-
-  virtual scoped_ptr<base::HistogramSamples> SnapshotSamples() const OVERRIDE;
-  virtual int FindCorruption(
-      const base::HistogramSamples& samples) const OVERRIDE;
-
- private:
-  const Stats* stats_;
-  DISALLOW_COPY_AND_ASSIGN(StatsHistogram);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_BLOCKFILE_STATS_HISTOGRAM_H_