[UMA] Remove redundant bucket_count variable from base::Histogram.

base/metrics/sparse_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 BASE_METRICS_SPARSE_HISTOGRAM_H_
 #define BASE_METRICS_SPARSE_HISTOGRAM_H_
 
 #include <map>
 #include <string>
 
@@ skipping 46 matching lines @@
 class BASE_EXPORT_PRIVATE SparseHistogram : public HistogramBase {
  public:
   // If there's one with same name, return the existing one. If not, create a
   // new one.
   static HistogramBase* FactoryGet(const std::string& name, int32 flags);
 
   virtual ~SparseHistogram();
 
   // HistogramBase implementation:
   virtual HistogramType GetHistogramType() const OVERRIDE;
-  virtual bool HasConstructionArguments(Sample minimum,
-                                        Sample maximum,
-                                        size_t bucket_count) const OVERRIDE;
+  virtual bool HasConstructionArguments(
+      Sample expected_minimum,
+      Sample expected_maximum,
+      size_t expected_bucket_count) const OVERRIDE;
   virtual void Add(Sample value) OVERRIDE;
   virtual void AddSamples(const HistogramSamples& samples) OVERRIDE;
   virtual bool AddSamplesFromPickle(PickleIterator* iter) OVERRIDE;
   virtual scoped_ptr<HistogramSamples> SnapshotSamples() const OVERRIDE;
   virtual void WriteHTMLGraph(std::string* output) const OVERRIDE;
   virtual void WriteAscii(std::string* output) const OVERRIDE;
 
  protected:
   // HistogramBase implementation:
   virtual bool SerializeInfoImpl(Pickle* pickle) const OVERRIDE;
@@ skipping 27 matching lines @@
   mutable base::Lock lock_;
 
   SampleMap samples_;
 
   DISALLOW_COPY_AND_ASSIGN(SparseHistogram);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_SPARSE_HISTOGRAM_H_