Media Controls: make the MediaControlsOverlayPlayButton a runtime enabled flag.

chromecast/renderer/cast_content_renderer_client.cc

Index: chromecast/renderer/cast_content_renderer_client.cc
diff --git a/chromecast/renderer/cast_content_renderer_client.cc b/chromecast/renderer/cast_content_renderer_client.cc
index 57089adefc565527a85bf185f75c3a341b5b0280..2092aa1d43f07318ed2bb2d68aab4bb6c3579b29 100644
--- a/chromecast/renderer/cast_content_renderer_client.cc
+++ b/chromecast/renderer/cast_content_renderer_client.cc
@@ -26,6 +26,7 @@
 #include "services/service_manager/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/platform/WebColor.h"
 #include "third_party/WebKit/public/web/WebFrameWidget.h"
+#include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "third_party/WebKit/public/web/WebSettings.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
@@ -98,9 +99,6 @@ void CastContentRendererClient::RenderViewCreated(
     blink::WebFrameWidget* web_frame_widget = render_view->GetWebFrameWidget();
     web_frame_widget->setBaseBackgroundColor(kColorBlack);
 
-    // Settings for ATV (Android defaults are not what we want):
-    webview->settings()->setMediaControlsOverlayPlayButtonEnabled(false);
-
     // Disable application cache as Chromecast doesn't support off-line
     // application running.
     webview->settings()->setOfflineWebApplicationCacheEnabled(false);
@@ -148,5 +146,11 @@ bool CastContentRendererClient::AllowMediaSuspend() {
   return false;
 }
 
+void CastContentRendererClient::
+    SetRuntimeFeaturesDefaultsBeforeBlinkInitialization() {
+  // Settings for ATV (Android defaults are not what we want).
+  blink::WebRuntimeFeatures::enableMediaControlsOverlayPlayButton(false);
+}
+
 }  // namespace shell
 }  // namespace chromecast