Reduce Histogram object size.

base/metrics/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.
 
 // Histogram is an object that aggregates statistics, and can summarize them in
 // various forms, including ASCII graphical, HTML, and numerically (as a
 // vector of numbers corresponding to each of the aggregating buckets).
 
 // It supports calls to accumulate either time intervals (which are processed
 // as integral number of milliseconds), or arbitrary integral units.
@@ skipping 155 matching lines @@
   // consistent with the bucket ranges and checksums in our histogram.  This can
   // produce a false-alarm if a race occurred in the reading of the data during
   // a SnapShot process, but should otherwise be false at all times (unless we
   // have memory over-writes, or DRAM failures). Flag definitions are located
   // under "enum Inconsistency" in base/metrics/histogram_base.h.
   uint32_t FindCorruption(const HistogramSamples& samples) const override;
 
   //----------------------------------------------------------------------------
   // Accessors for factory construction, serialization and testing.
   //----------------------------------------------------------------------------
-  Sample declared_min() const { return declared_min_; }
-  Sample declared_max() const { return declared_max_; }
+  Sample declared_min() const;
+  Sample declared_max() const;
   virtual Sample ranges(uint32_t i) const;
   virtual uint32_t bucket_count() const;
   const BucketRanges* bucket_ranges() const { return bucket_ranges_; }
 
   // This function validates histogram construction arguments. It returns false
   // if some of the arguments are bad but also corrects them so they should
   // function on non-dcheck builds without crashing.
   // Note. Currently it allow some bad input, e.g. 0 as minimum, but silently
   // converts it to good input: 1.
   // TODO(bcwhite): Use false returns to create "sink" histograms so that bad
@@ skipping 110 matching lines @@
   // WriteJSON calls these.
   void GetParameters(DictionaryValue* params) const override;
 
   void GetCountAndBucketData(Count* count,
                              int64_t* sum,
                              ListValue* buckets) const override;
 
   // Does not own this object. Should get from StatisticsRecorder.
   const BucketRanges* bucket_ranges_;
 
-  Sample declared_min_;  // Less than this goes into the first bucket.
-  Sample declared_max_;  // Over this goes into the last bucket.
-
   // Samples that have not yet been logged with SnapshotDelta().
   std::unique_ptr<HistogramSamples> unlogged_samples_;
 
   // Accumulation of all samples that have been logged with SnapshotDelta().
   std::unique_ptr<HistogramSamples> logged_samples_;
 
+#if DCHECK_IS_ON()  // Don't waste memory if it won't be used.
   // Flag to indicate if PrepareFinalDelta has been previously called. It is
   // used to DCHECK that a final delta is not created multiple times.
   mutable bool final_delta_created_ = false;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(Histogram);
 };
 
 //------------------------------------------------------------------------------
 
 // LinearHistogram is a more traditional histogram, with evenly spaced
 // buckets.
 class BASE_EXPORT LinearHistogram : public Histogram {
  public:
@@ skipping 209 matching lines @@
   static HistogramBase* DeserializeInfoImpl(base::PickleIterator* iter);
 
   static bool ValidateCustomRanges(const std::vector<Sample>& custom_ranges);
 
   DISALLOW_COPY_AND_ASSIGN(CustomHistogram);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_H_