Disk cache: Remove stats_histogram.

net/disk_cache/blockfile/stats.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_H_
 #define NET_DISK_CACHE_BLOCKFILE_STATS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "net/disk_cache/blockfile/addr.h"
-#include "net/disk_cache/blockfile/stats_histogram.h"
 
 namespace base {
 class HistogramSamples;
 }  // namespace base
 
 namespace disk_cache {
 
 typedef std::vector<std::pair<std::string, std::string> > StatsItems;
 
 // This class stores cache-specific usage information, for tunning purposes.
@@ skipping 52 matching lines @@
   int GetResurrectRatio() const;
   void ResetRatios();
 
   // Returns the lower bound of the space used by entries bigger than 512 KB.
   int GetLargeEntriesSize();
 
   // Writes the stats into |data|, to be stored at the given cache address.
   // Returns the number of bytes copied.
   int SerializeStats(void* data, int num_bytes, Addr* address);
 
-  // Support for StatsHistograms. Together, these methods allow StatsHistograms
-  // to take a snapshot of the data_sizes_ as the histogram data.
+ private:
+  // Supports generation of SizeStats histogram data.
   int GetBucketRange(size_t i) const;
-  void Snapshot(base::HistogramSamples* samples) const;
-
- private:
   int GetStatsBucket(int32 size);
   int GetRatio(Counters hit, Counters miss) const;
 
   Addr storage_addr_;
   int data_sizes_[kDataSizesLength];
   int64 counters_[MAX_COUNTER];
-  StatsHistogram* size_histogram_;
 
   DISALLOW_COPY_AND_ASSIGN(Stats);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_BLOCKFILE_STATS_H_