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

base/metrics/statistics_recorder_unittest.cc

Index: base/metrics/statistics_recorder_unittest.cc
diff --git a/base/metrics/statistics_recorder_unittest.cc b/base/metrics/statistics_recorder_unittest.cc
index ea91e8e8e9b601e90b8658d429e789b26ffccefb..22504ddfdda7e64c1b7bb21942d5839f8c911397 100644
--- a/base/metrics/statistics_recorder_unittest.cc
+++ b/base/metrics/statistics_recorder_unittest.cc
@@ -36,7 +36,11 @@ class StatisticsRecorderTest : public testing::Test {
                              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) {