Add ownership-transfer to histogram management calls.

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 86 matching lines @@
 class PickleIterator;
 class SampleVector;
 
 class BASE_EXPORT Histogram : public HistogramBase {
  public:
   // Initialize maximum number of buckets in histograms as 16,384.
   static const uint32_t kBucketCount_MAX;
 
   typedef std::vector<Count> Counts;
 
+  ~Histogram() override;
+
   //----------------------------------------------------------------------------
   // For a valid histogram, input should follow these restrictions:
   // minimum > 0 (if a minimum below 1 is specified, it will implicitly be
   //              normalized up to 1)
   // maximum > minimum
   // buckets > 2 [minimum buckets needed: underflow, overflow and the range]
   // Additionally,
   // buckets <= (maximum - minimum + 2) - this is to ensure that we don't have
   // more buckets than the range of numbers; having more buckets than 1 per
   // value in the range would be nonsensical.
@@ skipping 113 matching lines @@
   Histogram(const std::string& name,
             Sample minimum,
             Sample maximum,
             const BucketRanges* ranges,
             HistogramBase::AtomicCount* counts,
             HistogramBase::AtomicCount* logged_counts,
             uint32_t counts_size,
             HistogramSamples::Metadata* meta,
             HistogramSamples::Metadata* logged_meta);
 
-  ~Histogram() override;
-
   // HistogramBase implementation:
   bool SerializeInfoImpl(base::Pickle* pickle) const override;
 
   // Method to override to skip the display of the i'th bucket if it's empty.
   virtual bool PrintEmptyBucket(uint32_t index) const;
 
   // Get normalized size, relative to the ranges(i).
   virtual double GetBucketSize(Count current, uint32_t i) const;
 
   // Return a string description of what goes in a given bucket.
@@ skipping 282 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_