Use lock-free lazy initialization for static histogram references

net/disk_cache/stats.h

 // Copyright (c) 2011 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.
 
 #ifndef NET_DISK_CACHE_STATS_H_
 #define NET_DISK_CACHE_STATS_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 68 matching lines @@
   void Snapshot(StatsHistogram::StatsSamples* samples) const;
 
  private:
   int GetStatsBucket(int32 size);
   int GetRatio(Counters hit, Counters miss) const;
 
   BackendImpl* backend_;
   uint32 storage_addr_;
   int data_sizes_[kDataSizesLength];
   int64 counters_[MAX_COUNTER];
-  scoped_refptr<StatsHistogram> size_histogram_;
+  StatsHistogram* size_histogram_;

[rvargas (doing something else), 2011/04/01 19:20:52]

Can we have a scoped_ptr instead?. Probably not... never mind then.

[jar (doing other things), 2011/04/01 21:50:27]

Since we're deliberately leaking all of these, we don't want to delete, since
others are depending on the eternally correct raw pointer (to memory that will
be leaked).

 
   DISALLOW_COPY_AND_ASSIGN(Stats);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_STATS_H_