Enable media stream layout test with content_shell.

content/shell/shell_content_renderer_client.cc

Index: content/shell/shell_content_renderer_client.cc
===================================================================
--- content/shell/shell_content_renderer_client.cc	(revision 191534)
+++ content/shell/shell_content_renderer_client.cc	(working copy)
@@ -20,8 +20,10 @@
 #include "third_party/WebKit/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestInterfaces.h"
 #include "third_party/WebKit/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestProxy.h"
 #include "third_party/WebKit/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestRunner.h"
+#include "third_party/WebKit/Tools/DumpRenderTree/chromium/TestRunner/public/WebUserMediaClientMock.h"
 #include "v8/include/v8.h"
 #include "webkit/mocks/mock_webhyphenator.h"
+#include "webkit/support/test_media_stream_client.h"
 #include "webkit/tools/test_shell/mock_webclipboard_impl.h"
 #include "webkit/tools/test_shell/test_shell_webmimeregistry_impl.h"
 
@@ -115,6 +117,34 @@
 #endif
 }
 
+WebKit::WebUserMediaClient*
+ShellContentRendererClient::OverrideUserMediaClient() {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree))
+    return NULL;
+#if defined(ENABLE_WEBRTC)
+  if (!user_media_client_) {
+    user_media_client_.reset(new WebTestRunner::WebUserMediaClientMock(
+        ShellRenderProcessObserver::GetInstance()->test_delegate()));
+  }
+  return user_media_client_.get();
+#else
+  return NULL;
+#endif
+}
+
+webkit_media::MediaStreamClient*
+ShellContentRendererClient::OverrideMediaStreamClient() {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree))
+    return NULL;
+#if defined(ENABLE_WEBRTC)
+  if (!media_stream_client_)
+    media_stream_client_.reset(new webkit_support::TestMediaStreamClient());
+  return media_stream_client_.get();
+#else
+  return NULL;
+#endif
+}
+
 WebRTCPeerConnectionHandler*
 ShellContentRendererClient::OverrideCreateWebRTCPeerConnectionHandler(
     WebRTCPeerConnectionHandlerClient* client) {