Use the browser UI thread for audio on OSX.

media/audio/audio_output_controller_unittest.cc

Index: media/audio/audio_output_controller_unittest.cc
diff --git a/media/audio/audio_output_controller_unittest.cc b/media/audio/audio_output_controller_unittest.cc
index c6c2d4572a05d935c2428c1a5ac844b9dcadeccf..c3cfa09df6d82121850f0b1b223be5b9fda7ea3b 100644
--- a/media/audio/audio_output_controller_unittest.cc
+++ b/media/audio/audio_output_controller_unittest.cc
@@ -4,11 +4,9 @@
 
 #include "base/basictypes.h"
 #include "base/bind.h"
-#include "base/environment.h"
 #include "base/logging.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
 #include "base/synchronization/waitable_event.h"
 #include "media/audio/audio_output_controller.h"
 #include "media/audio/audio_parameters.h"
@@ -222,9 +220,14 @@ class AudioOutputControllerTest : public testing::Test {
 
   void Close() {
     EXPECT_CALL(mock_sync_reader_, Close());
+    base::WaitableEvent close_event(true, false);
+    base::Closure closed_cb = base::Bind(
+        &base::WaitableEvent::Signal, base::Unretained(&close_event));
 
-    controller_->Close(base::MessageLoop::QuitClosure());
-    base::MessageLoop::current()->Run();
+    audio_manager_->GetMessageLoop()->PostTask(
+        FROM_HERE,
+        base::Bind(&AudioOutputController::Close, controller_, closed_cb));
+    close_event.Wait();
   }
 
   // These help make test sequences more readable.
@@ -249,7 +252,6 @@ class AudioOutputControllerTest : public testing::Test {
   void WaitForPause() { pause_event_.Wait(); }
 
  private:
-  base::MessageLoopForIO message_loop_;
   scoped_ptr<AudioManager> audio_manager_;
   MockAudioOutputControllerEventHandler mock_event_handler_;
   MockAudioOutputControllerSyncReader mock_sync_reader_;