Fix a memory leak caused by AudioRenedererHost.

chrome/browser/renderer_host/audio_renderer_host.h

 // Copyright (c) 2006-2009 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.
 //
 // AudioRendererHost serves audio related requests from AudioRenderer which
 // lives inside the render process and provide access to audio hardware. It maps
 // an internal ID to AudioRendererHost::IPCAudioSource in a map, which is the
 // actual object providing audio packets through IPC. It creates the actual
 // AudioOutputStream object when requested by the renderer and returns an
 // internal ID. It then delegates calls to the AudioOutputStream object indexed
@@ skipping 14 matching lines @@
 // streams are also created in the IO thread, so we need to destroy them also
 // in IO thread. After this class is created, a task of OnInitialized() is
 // posted on IO thread in which singleton of AudioManager is created and
 // AddRef() is called to increase one ref count of this object. Owner of this
 // class should call Destroy() before decrementing the ref count to this object,
 // which essentially post a task of OnDestroyed() on IO thread. Inside
 // OnDestroyed(), audio output streams are destroyed and Release() is called
 // which may result in self-destruction.
 //
 // TODO(hclam): Have these things done before having real implementations:
-//   1. Make sure this class has greater or equal lifetime to
+//   1. Make AudioManager a singleton and construct/destruct it properly.
+//   2. Make sure this class has greater or equal lifetime to
 //      IPC:Message::Sender, essentially ResourceMessageFilter.
-//   2. Listen to destruction event of the browser and do cleanup in case this
+//   3. Listen to destruction event of the browser and do cleanup in case this
 //      class is not destructed nicely during browser close.
 
 #ifndef CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_
 #define CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_
 
 #include "base/id_map.h"
 #include "base/ref_counted.h"
 #include "base/shared_memory.h"
 #include "chrome/common/ipc_message.h"
 #include "media/audio/audio_output.h"
@@ skipping 105 matching lines @@
   int32 next_id_;
 
   // Only used for DCHECKs to make sure all methods calls are from the same
   // thread as this object is created.
   MessageLoop* io_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererHost);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_