Do not use overlays when VR shell is enabled.

media/blink/webmediaplayer_impl.h

 // Copyright 2013 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 MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_
 #define MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 189 matching lines @@
 
   void SetMediaPlayerManager(
       RendererMediaPlayerManagerInterface* media_player_manager);
   void OnRemotePlaybackEnded();
   void OnDisconnectedFromRemoteDevice(double t);
   void SuspendForRemote();
   void DisplayCastFrameAfterSuspend(const scoped_refptr<VideoFrame>& new_frame,
                                     PipelineStatus status);
   gfx::Size GetCanvasSize() const;
   void SetDeviceScaleFactor(float scale_factor);
+  void SetDisableFullscreenOverlays(bool disable_overlays);

[liberato (no reviews please), 2016/12/13 23:03:29]

SetDisable is a little confusing.  SetAllowFullscreenOverlays(bool) might be
better.

also worth a comment that this is set by default during construction, and one
probably doesn't want to call it except for VR.  it'll screw up the experiment
results that are attached to kForceVideoOverlays if it's called too much.

actually, maybe DisableFullScreenOverlaysForVR() is a better name, so it's super
clear that one should not call this unless one is you. :) 

[amp, 2016/12/13 23:40:02]

I'm leaning towards SetAllowFullscreenOverlays and checking both features
instead of doing anything in the constructor.

I'm looking into if we can signal finch when the experiment data is invalid
because of vr shell.

[amp, 2016/12/14 00:04:51]

Yes it is possible to make finch ignore data when vr shell is enabled.  See
cl/141952159

   void setPoster(const blink::WebURL& poster) override;
   void SetUseFallbackPath(bool use_fallback_path);
 #endif
 
   // Called from WebMediaPlayerCast.
   // TODO(hubbe): WMPI_CAST make private.
   void OnPipelineSeeked(bool time_updated);
 
   // Restart the player/pipeline as soon as possible. This will destroy the
   // current renderer, if any, and create a new one via the RendererFactory; and
@@ skipping 358 matching lines @@
 
   // Whether the player is currently in autoplay muted state.
   bool autoplay_muted_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_WEBMEDIAPLAYER_IMPL_H_