Move StatisticsRecorder out of histogram.cc/h for further refactoring.

net/disk_cache/stats_histogram.cc

 // Copyright (c) 2011 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 "net/disk_cache/stats_histogram.h"
 
 #include "base/debug/leak_annotations.h"
 #include "base/logging.h"
+#include "base/metrics/statistics_recorder.h"
 #include "net/disk_cache/stats.h"
 
 namespace disk_cache {
 
 using base::Histogram;
 using base::StatisticsRecorder;
 
 // Static.
 const Stats* StatsHistogram::stats_ = NULL;
 
@@ skipping 70 matching lines @@
   return NO_INCONSISTENCIES;  // This class won't monitor inconsistencies.
 }
 
 uint32 StatsHistogram::CalculateRangeChecksum() const {
   // We don't calculate checksums, so at least establish a unique constant.
   const uint32 kStatsHistogramChecksum = 0x0cecce;
   return kStatsHistogramChecksum;
 }
 
 }  // namespace disk_cache