Media Controls: make the MediaControlsOverlayPlayButton a runtime enabled flag.

chromecast/renderer/cast_content_renderer_client.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_
 #define CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 25 matching lines @@
   void RenderThreadStarted() override;
   void RenderViewCreated(content::RenderView* render_view) override;
   void AddSupportedKeySystems(
       std::vector<std::unique_ptr<::media::KeySystemProperties>>*
           key_systems_properties) override;
   blink::WebPrescientNetworking* GetPrescientNetworking() override;
   void DeferMediaLoad(content::RenderFrame* render_frame,
                       bool render_frame_has_played_media_before,
                       const base::Closure& closure) override;
   bool AllowMediaSuspend() override;
+  void SetRuntimeFeaturesDefaultsBeforeBlinkInitialization() override;
 
  protected:
   CastContentRendererClient();
 
   virtual void RunWhenInForeground(content::RenderFrame* render_frame,
                                    const base::Closure& closure);
 
  private:
   std::unique_ptr<network_hints::PrescientNetworkingDispatcher>
       prescient_networking_dispatcher_;
   std::unique_ptr<media::MediaCapsObserverImpl> media_caps_observer_;
   std::unique_ptr<media::SupportedCodecProfileLevelsMemo> supported_profiles_;
 
   const bool allow_hidden_media_playback_;
 
   DISALLOW_COPY_AND_ASSIGN(CastContentRendererClient);
 };
 
 }  // namespace shell
 }  // namespace chromecast
 
 #endif  // CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_