Fix race in HostSharedBitmapManager::AllocatedBitmapCount

content/common/host_shared_bitmap_manager.h

 // Copyright (c) 2013 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 CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_
 #define CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_
 
 #include <map>
 #include <set>
 
@@ skipping 47 matching lines @@
       size_t buffer_size,
       const cc::SharedBitmapId& id,
       base::SharedMemoryHandle* shared_memory_handle);
   void ChildAllocatedSharedBitmap(size_t buffer_size,
                                   const base::SharedMemoryHandle& handle,
                                   base::ProcessHandle process_handle,
                                   const cc::SharedBitmapId& id);
   void ChildDeletedSharedBitmap(const cc::SharedBitmapId& id);
   void ProcessRemoved(base::ProcessHandle process_handle);
 
-  size_t AllocatedBitmapCount() const { return handle_map_.size(); }
+  size_t AllocatedBitmapCount() const;
 
  private:
   void FreeSharedMemoryFromMap(cc::SharedBitmap* bitmap);
 
-  base::Lock lock_;
+  mutable base::Lock lock_;
 
   typedef base::hash_map<cc::SharedBitmapId, scoped_refptr<BitmapData> >
       BitmapMap;
   BitmapMap handle_map_;
 
   typedef base::hash_map<base::ProcessHandle,
                          base::hash_set<cc::SharedBitmapId> > ProcessMap;
   ProcessMap process_map_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_