Revert of Disable MediaStreamAudioTest.CallbackOnTrackInitialization on Mac.

content/renderer/media/media_stream_audio_unittest.cc

Index: content/renderer/media/media_stream_audio_unittest.cc
diff --git a/content/renderer/media/media_stream_audio_unittest.cc b/content/renderer/media/media_stream_audio_unittest.cc
index defbb51410b85f7b95bca729ec2fd19c03d716da..225e87b2cb09531d653169236dc3350ea9740240 100644
--- a/content/renderer/media/media_stream_audio_unittest.cc
+++ b/content/renderer/media/media_stream_audio_unittest.cc
@@ -460,15 +460,8 @@
   track()->RemoveSink(&sink);
 }
 
-// https://crbug.com/709231 tracks test failures on Mac10.9 Tests (dbg).
-#if defined(OS_MACOSX)
-#define MAYBE_CallbackOnTrackInitialization \
-  DISABLED_CallbackOnTrackInitialization
-#else
-#define MAYBE_CallbackOnTrackInitialization CallbackOnTrackInitialization
-#endif
 // Tests that a callback is fired when initialization completes on a track.
-TEST_F(MediaStreamAudioTest, MAYBE_CallbackOnTrackInitialization) {
+TEST_F(MediaStreamAudioTest, CallbackOnTrackInitialization) {
   // Create a source, connect it to track, and connect the track to a
   // sink.
   blink_audio_source_.setExtraData(new FakeMediaStreamAudioSource());