[Media Controls] Prevent flicker when enter/exit fullscreen

third_party/WebKit/Source/modules/media_controls/MediaControlsImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 554 matching lines @@
 }
 
 LayoutObject* MediaControlsImpl::PanelLayoutObject() {
   return panel_->GetLayoutObject();
 }
 
 LayoutObject* MediaControlsImpl::ContainerLayoutObject() {
   return GetLayoutObject();
 }
 
-void MediaControlsImpl::Show() {
-  MakeOpaque();
+void MediaControlsImpl::MaybeShow() {
   panel_->SetIsWanted(true);
   panel_->SetIsDisplayed(true);
   if (overlay_play_button_)
     overlay_play_button_->UpdateDisplayType();
+  // Only make the controls visible if they won't get hidden by OnTimeUpdate.
+  if (MediaElement().paused() || !ShouldHideMediaControls())
+    MakeOpaque();
 }
 
 void MediaControlsImpl::Hide() {
   panel_->SetIsWanted(false);
   panel_->SetIsDisplayed(false);
   if (overlay_play_button_)
     overlay_play_button_->SetIsWanted(false);
 }
 
 bool MediaControlsImpl::IsVisible() const {
@@ skipping 313 matching lines @@
   BatchedControlUpdate batch(this);
   volume_slider_->SetIsWanted(MediaElement().HasAudio() &&
                               !PreferHiddenVolumeControls(GetDocument()));
   mute_button_->SetIsWanted(MediaElement().HasAudio());
 }
 
 void MediaControlsImpl::OnFocusIn() {
   if (!MediaElement().ShouldShowControls())
     return;
 
-  Show();
   ResetHideMediaControlsTimer();
+  MaybeShow();
 }
 
 void MediaControlsImpl::OnTimeUpdate() {
   timeline_->SetPosition(MediaElement().currentTime());
   UpdateCurrentTimeDisplay();
 
   // 'timeupdate' might be called in a paused state. The controls should not
   // become transparent in that case.
   if (MediaElement().paused()) {
     MakeOpaque();
@@ skipping 289 matching lines @@
   visitor->Trace(overlay_cast_button_);
   visitor->Trace(media_event_listener_);
   visitor->Trace(window_event_listener_);
   visitor->Trace(orientation_lock_delegate_);
   visitor->Trace(rotate_to_fullscreen_delegate_);
   MediaControls::Trace(visitor);
   HTMLDivElement::Trace(visitor);
 }
 
 }  // namespace blink