Reland 10000004 - Make the CancellableSyncSocket non-blocking on Send, and blocking on Receive

content/browser/renderer_host/media/audio_sync_reader.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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_SYNC_READER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_SYNC_READER_H_
 #pragma once
 
 #include "base/file_descriptor_posix.h"
 #include "base/process.h"
@@ skipping 34 matching lines @@
   base::SharedMemory* shared_memory_;
   base::Time previous_call_time_;
 
   // Socket for transmitting audio data.
   scoped_ptr<base::CancelableSyncSocket> socket_;
 
   // Socket to be used by the renderer. The reference is released after
   // PrepareForeignSocketHandle() is called and ran successfully.
   scoped_ptr<base::CancelableSyncSocket> foreign_socket_;
 
-  // Protect socket_ access by lock to prevent race condition when audio
-  // controller thread closes the reader and hardware audio thread is reading
-  // data. This way we know that socket would not be deleted while we are
-  // writing data to it.
-  base::Lock lock_;
-
   DISALLOW_COPY_AND_ASSIGN(AudioSyncReader);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_SYNC_READER_H_