Remove calls to MessageLoop::current() in media.

media/audio/audio_output_device.cc

Index: media/audio/audio_output_device.cc
diff --git a/media/audio/audio_output_device.cc b/media/audio/audio_output_device.cc
index e618b3b5242f41ee4838137099788cf36ec1ad4c..42d52ce1e557745d2cd85d491b7ec920390eb8e8 100644
--- a/media/audio/audio_output_device.cc
+++ b/media/audio/audio_output_device.cc
@@ -14,6 +14,7 @@
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "base/trace_event/trace_event.h"
@@ -118,7 +119,7 @@ void AudioOutputDevice::Start() {
 void AudioOutputDevice::Stop() {
   {
     base::AutoLock auto_lock(audio_thread_lock_);
-    audio_thread_.Stop(base::MessageLoop::current());
+    audio_thread_.Stop(base::ThreadTaskRunnerHandle::Get());
     stopping_hack_ = true;
   }