Use a shared thread for media operations.

webkit/mocks/test_media_stream_client.h

Index: webkit/mocks/test_media_stream_client.h
diff --git a/webkit/mocks/test_media_stream_client.h b/webkit/mocks/test_media_stream_client.h
index 0f5c65af8abcc822d6788716b4aba1bcff3e0cb6..7e599b3c5592834cd24c9629c68288acd48e03d5 100644
--- a/webkit/mocks/test_media_stream_client.h
+++ b/webkit/mocks/test_media_stream_client.h
@@ -10,29 +10,14 @@
 #define WEBKIT_MOCKS_TEST_MEDIA_STREAM_CLIENT_H_
 
 #include "base/callback_forward.h"
-#include "third_party/WebKit/Source/Platform/chromium/public/WebURL.h"
 #include "webkit/media/media_stream_client.h"
 
-namespace WebKit {
-class WebFrame;
-class WebMediaPlayer;
-class WebMediaPlayerClient;
-}
-
 namespace webkit_media {
 class MediaStreamAudioRenderer;
-class MediaStreamClient;
 }
 
 namespace webkit_glue {
 
-// This is used by WebFrameClient::createMediaPlayer().
-WebKit::WebMediaPlayer* CreateMediaPlayer(
-    WebKit::WebFrame* frame,
-    const WebKit::WebURL& url,
-    WebKit::WebMediaPlayerClient* client,
-    webkit_media::MediaStreamClient* media_stream_client);
-
 class TestMediaStreamClient : public webkit_media::MediaStreamClient {
  public:
   TestMediaStreamClient();