Add thread safety to AudioManagerBase to protect access to the audio thread member variable.

media/audio/audio_low_latency_input_output_unittest.cc

 // 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.
 
 #include "base/basictypes.h"
 #include "base/environment.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/synchronization/lock.h"
 #include "base/test/test_timeouts.h"
 #include "base/time.h"
 #include "base/win/scoped_com_initializer.h"
 #include "build/build_config.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_util.h"
 #if defined(OS_LINUX) || defined(OS_OPENBSD)
@@ skipping 56 matching lines @@
 // the GetMessageLoop() method to ensure that we can run our tests on
 // the main thread instead of the audio thread.
 class MockAudioManager : public AudioManagerAnyPlatform {
  public:
   MockAudioManager() {
     Init();
   }
 
   virtual ~MockAudioManager() {}
 
-  virtual MessageLoop* GetMessageLoop() OVERRIDE {
-    return MessageLoop::current();
+  virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() OVERRIDE {
+    return MessageLoop::current()->message_loop_proxy();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockAudioManager);
 };
 
 // Test fixture class.
 class AudioLowLatencyInputOutputTest : public testing::Test {
  protected:
   AudioLowLatencyInputOutputTest()
@@ skipping 353 matching lines @@
   aos->Stop();
   ais->Stop();
 
   // All Close() operations that run on the mocked audio thread,
   // should be synchronous and not post additional close tasks to
   // mocked the audio thread. Hence, there is no need to call
   // message_loop()->RunAllPending() after the Close() methods.
   aos->Close();
   ais->Close();
 }