Run |demuxer_| related tasks in the media thread in GTV.

content/renderer/media/android/webmediaplayer_android.h

Index: content/renderer/media/android/webmediaplayer_android.h
diff --git a/content/renderer/media/android/webmediaplayer_android.h b/content/renderer/media/android/webmediaplayer_android.h
index e149d442e3e3f9449b5d46bf893075a598181818..03f511cbb0eb9d7c03700d9b62865c04fe227dc6 100644
--- a/content/renderer/media/android/webmediaplayer_android.h
+++ b/content/renderer/media/android/webmediaplayer_android.h
@@ -77,6 +77,7 @@ class WebMediaPlayerAndroid
       RendererMediaPlayerManager* manager,
       WebMediaPlayerProxyAndroid* proxy,
       StreamTextureFactory* factory,
+      const scoped_refptr<base::MessageLoopProxy>& media_loop,
       media::MediaLog* media_log);
   virtual ~WebMediaPlayerAndroid();
 
@@ -303,6 +304,9 @@ class WebMediaPlayerAndroid
   // Message loop for main renderer thread.
   const scoped_refptr<base::MessageLoopProxy> main_loop_;
 
+  // Message loop for media thread.
+  const scoped_refptr<base::MessageLoopProxy> media_loop_;
+
   // URL of the media file to be fetched.
   GURL url_;