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

base/metrics/statistics_recorder_unittest.cc

 // 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.
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 18 matching lines @@
 
   void UninitializeStatisticsRecorder() {
     delete statistics_recorder_;
     statistics_recorder_ = NULL;
   }
 
   Histogram* CreateHistogram(const std::string& name,
                              HistogramBase::Sample min,
                              HistogramBase::Sample max,
                              size_t bucket_count) {
-    return new Histogram(name, min, max, bucket_count, NULL);
+    BucketRanges* ranges = new BucketRanges(bucket_count + 1);
+    Histogram::InitializeBucketRanges(min, max, ranges);
+    const BucketRanges* registered_ranges =
+        StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges);
+    return new Histogram(name, min, max, registered_ranges);
   }
 
   void DeleteHistogram(HistogramBase* histogram) {
     delete histogram;
   }
 
   StatisticsRecorder* statistics_recorder_;
 };
 
 TEST_F(StatisticsRecorderTest, NotInitialized) {
@@ skipping 203 matching lines @@
   EXPECT_EQ(1u, ranges.size());
 
   Histogram::FactoryGet("Histogram3", 1, 64, 16, HistogramBase::kNoFlags);
 
   ranges.clear();
   StatisticsRecorder::GetBucketRanges(&ranges);
   EXPECT_EQ(2u, ranges.size());
 }
 
 }  // namespace base