Hide fullscreen rotation jank

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index a2a4fd1692dd510c9f49ab2ea91e2f3d9fdf7c0f..b44986af2d8609db384ac805863e466ea8c42043 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1137,6 +1137,12 @@ void RenderWidgetHostViewAndroid::DidCreateNewRendererCompositorFrameSink() {
 void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
     const cc::LocalSurfaceId& local_surface_id,
     cc::CompositorFrame frame) {
+  // In fullscreen, prevent background from flashing white.

[Khushal, 2017/04/12 01:56:55]

Like we were discussing this will still miss a few cases.

1) This call only happens when you get a new frame. So till the time there is no
update from the renderer, you won't see any change.

2) For the transition into video, you'll still see the stale frame. Except the
area not drawn will be black.

May be the better thing to do is to draw black instead of the stale frame when
we go fullscreen in the browser, until we wait for the renderer's corresponding
frame.

+  if (content_view_core_ &&
+      content_view_core_->GetWebContents()->IsFullscreen()) {
+    frame.metadata.root_background_color = SK_ColorBLACK;
+  }
+
   last_scroll_offset_ = frame.metadata.root_scroll_offset;
   DCHECK(delegated_frame_host_);
   DCHECK(!frame.render_pass_list.empty());