Add ownership-transfer to histogram management calls.

base/metrics/statistics_recorder.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.
 
 // StatisticsRecorder holds all Histograms and BucketRanges that are used by
 // Histograms in the system. It provides a general place for
 // Histograms/BucketRanges to register, and supports a global API for accessing
 // (i.e., dumping, or graphing) the data.
 
 #ifndef BASE_METRICS_STATISTICS_RECORDER_H_
@@ skipping 55 matching lines @@
   // Initializes the StatisticsRecorder system. Safe to call multiple times.
   static void Initialize();
 
   // Find out if histograms can now be registered into our list.
   static bool IsActive();
 
   // Register, or add a new histogram to the collection of statistics. If an
   // identically named histogram is already registered, then the argument
   // |histogram| will deleted.  The returned value is always the registered
   // histogram (either the argument, or the pre-existing registered histogram).
-  static HistogramBase* RegisterOrDeleteDuplicate(HistogramBase* histogram);
+  static HistogramBase* RegisterOrDeleteDuplicate(
+      scoped_ptr<HistogramBase> histogram);
 
   // Register, or add a new BucketRanges. If an identically BucketRanges is
   // already registered, then the argument |ranges| will deleted. The returned
   // value is always the registered BucketRanges (either the argument, or the
   // pre-existing one).
   static const BucketRanges* RegisterOrDeleteDuplicateRanges(
-      const BucketRanges* ranges);
+      scoped_ptr<const BucketRanges> ranges);
 
   // Methods for appending histogram data to a string.  Only histograms which
   // have |query| as a substring are written to |output| (an empty string will
   // process all registered histograms).
   static void WriteHTMLGraph(const std::string& query, std::string* output);
   static void WriteGraph(const std::string& query, std::string* output);
 
   // Returns the histograms with |query| as a substring as JSON text (an empty
   // |query| will process all registered histograms).
   static std::string ToJSON(const std::string& query);
@@ skipping 81 matching lines @@
 
   // Lock protects access to above maps.
   static base::Lock* lock_;
 
   DISALLOW_COPY_AND_ASSIGN(StatisticsRecorder);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_STATISTICS_RECORDER_H_