Revert 119769 - Switch AudioDevice classes from SyncSocket to CancelableSyncSocket.

content/renderer/media/audio_device.h

Index: content/renderer/media/audio_device.h
===================================================================
--- content/renderer/media/audio_device.h	(revision 119920)
+++ content/renderer/media/audio_device.h	(working copy)
@@ -142,6 +142,33 @@
   virtual void OnVolume(double volume) OVERRIDE;
 
  private:
+  // Encapsulate socket into separate class to avoid double-close.
+  // Class is ref-counted to avoid potential race condition if audio device
+  // is deleted simultaneously with audio thread stopping.
+  class AudioSocket : public base::RefCountedThreadSafe<AudioSocket> {
+   public:
+    explicit AudioSocket(base::SyncSocket::Handle socket_handle)
+        : socket_(socket_handle) {
+    }
+    base::SyncSocket* socket() {
+      return &socket_;
+    }
+    void Close() {
+      // Close() should be thread-safe, obtain the lock.
+      base::AutoLock auto_lock(lock_);
+      socket_.Close();
+    }
+
+   private:
+    // Magic required by ref_counted.h to avoid any code deleting the object
+    // accidentally while there are references to it.
+    friend class base::RefCountedThreadSafe<AudioSocket>;
+    ~AudioSocket() { }
+
+    base::Lock lock_;
+    base::SyncSocket socket_;
+  };
+
   // Magic required by ref_counted.h to avoid any code deleting the object
   // accidentally while there are references to it.
   friend class base::RefCountedThreadSafe<AudioDevice>;
@@ -221,7 +248,7 @@
   // These variables must only be set on the IO thread while the audio_thread_
   // is not running.
   base::SharedMemoryHandle shared_memory_handle_;
-  scoped_ptr<base::CancelableSyncSocket> audio_socket_;
+  scoped_refptr<AudioSocket> audio_socket_;
   int memory_length_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDevice);