Set WebMediaPlayer as an opaque layer

content/renderer/media/webmediaplayer_ms.cc

Index: content/renderer/media/webmediaplayer_ms.cc
diff --git a/content/renderer/media/webmediaplayer_ms.cc b/content/renderer/media/webmediaplayer_ms.cc
index e60ae7681397c8591fd5c658d492284fa38547cb..68a48e26ad7230075f27667806cb7cbb0e9c4fc4 100644
--- a/content/renderer/media/webmediaplayer_ms.cc
+++ b/content/renderer/media/webmediaplayer_ms.cc
@@ -509,7 +509,7 @@ void WebMediaPlayerMS::OnFrameAvailable(
 
       video_weblayer_.reset(new cc_blink::WebLayerImpl(
           cc::VideoLayer::Create(compositor_.get(), video_rotation_)));
-      video_weblayer_->layer()->SetContentsOpaque(false);
+      video_weblayer_->layer()->SetContentsOpaque(true);
       video_weblayer_->SetContentsOpaqueIsFixed(true);
       get_client()->setWebLayer(video_weblayer_.get());
     }