Enable media stream layout test with content_shell.

content/shell/shell_content_renderer_client.h

Index: content/shell/shell_content_renderer_client.h
===================================================================
--- content/shell/shell_content_renderer_client.h	(revision 191534)
+++ content/shell/shell_content_renderer_client.h	(working copy)
@@ -18,12 +18,17 @@
 
 namespace WebTestRunner {
 class WebTestProxyBase;
+class WebUserMediaClientMock;
 }
 
 namespace webkit_glue {
 class MockWebHyphenator;
 }
 
+namespace webkit_support {
+class TestMediaStreamClient;
+}
+
 class MockWebClipboardImpl;
 class TestShellWebMimeRegistryImpl;
 
@@ -48,6 +53,8 @@
       WebKit::WebPlugin** plugin) OVERRIDE;
   virtual WebKit::WebMediaStreamCenter* OverrideCreateWebMediaStreamCenter(
       WebKit::WebMediaStreamCenterClient* client) OVERRIDE;
+  virtual WebKit::WebUserMediaClient* OverrideUserMediaClient() OVERRIDE;
+  virtual webkit_media::MediaStreamClient* OverrideMediaStreamClient() OVERRIDE;
   virtual WebKit::WebRTCPeerConnectionHandler*
   OverrideCreateWebRTCPeerConnectionHandler(
       WebKit::WebRTCPeerConnectionHandlerClient* client) OVERRIDE;
@@ -66,6 +73,8 @@
   scoped_ptr<MockWebClipboardImpl> clipboard_;
   scoped_ptr<TestShellWebMimeRegistryImpl> mime_registry_;
   scoped_ptr<webkit_glue::MockWebHyphenator> hyphenator_;
+  scoped_ptr<WebTestRunner::WebUserMediaClientMock> user_media_client_;
+  scoped_ptr<webkit_support::TestMediaStreamClient> media_stream_client_;
 };
 
 }  // namespace content