This is a major refactor of Histogram related code:

1. Remove duplicated code from histogram.h/.cc,
   including validating related code and BucketRanges related.
2. Constness of BucketRanges from Histograms, to prevent accidentally modification and provide a simpler interface.
3. Add/move tests.

Review URL: https://chromiumcodereview.appspot.com/10834011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149495 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 7 insertions, 16 deletions

diff --git a/net/disk_cache/stats_histogram.cc b/net/disk_cache/stats_histogram.cc
index 66c8e50..d3bab34 100644
--- a/net/disk_cache/stats_histogram.cc
+++ b/net/disk_cache/stats_histogram.cc
@@ -33,20 +33,16 @@ StatsHistogram* StatsHistogram::FactoryGet(const std::string& name) {
     // To avoid racy destruction at shutdown, the following will be leaked.
     StatsHistogram* stats_histogram =
         new StatsHistogram(name, minimum, maximum, bucket_count);
-    stats_histogram->InitializeBucketRange();
     stats_histogram->SetFlags(kUmaTargetedHistogramFlag);
     histogram = StatisticsRecorder::RegisterOrDeleteDuplicate(stats_histogram);
   }
 
   DCHECK(HISTOGRAM == histogram->histogram_type());
-  DCHECK(histogram->HasConstructorArguments(minimum, maximum, bucket_count));
+  DCHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count));
 
   // We're preparing for an otherwise unsafe upcast by ensuring we have the
   // proper class type.
   StatsHistogram* return_histogram = static_cast<StatsHistogram*>(histogram);
-  // Validate upcast by seeing that we're probably providing the checksum.
-  CHECK_EQ(return_histogram->StatsHistogram::CalculateRangeChecksum(),
-           return_histogram->CalculateRangeChecksum());
   return return_histogram;
 }
 
@@ -87,10 +83,4 @@ Histogram::Inconsistencies StatsHistogram::FindCorruption(
   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
diff --git a/net/disk_cache/stats_histogram.h b/net/disk_cache/stats_histogram.h
index 97b2d401..f3af304 100644
--- a/net/disk_cache/stats_histogram.h
+++ b/net/disk_cache/stats_histogram.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -29,9 +29,11 @@ class StatsHistogram : public base::Histogram {
     }
   };
 
-  StatsHistogram(const std::string& name, Sample minimum,
-                 Sample maximum, size_t bucket_count)
-      : Histogram(name, minimum, maximum, bucket_count), init_(false) {}
+  StatsHistogram(const std::string& name,
+                 Sample minimum,
+                 Sample maximum,
+                 size_t bucket_count)
+      : Histogram(name, minimum, maximum, bucket_count, NULL), init_(false) {}
   virtual ~StatsHistogram();
 
   static StatsHistogram* FactoryGet(const std::string& name);
@@ -44,7 +46,6 @@ class StatsHistogram : public base::Histogram {
   virtual void SnapshotSample(SampleSet* sample) const OVERRIDE;
   virtual Inconsistencies FindCorruption(
       const SampleSet& snapshot) const OVERRIDE;
-  virtual uint32 CalculateRangeChecksum() const OVERRIDE;
 
  private:
   bool init_;