Implement FullScreen using top layer.

third_party/WebKit/Source/web/FullscreenController.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 160 matching lines @@
         frame->client()->exitFullscreen();
 }
 
 void FullscreenController::updateSize()
 {
     if (!isFullscreen())
         return;
 
     updatePageScaleConstraints(false);
 
-    LayoutFullScreen* layoutObject = Fullscreen::from(*m_fullScreenFrame->document()).fullScreenLayoutObject();
-    if (layoutObject)
-        layoutObject->updateStyle();
+    Document* document = m_fullScreenFrame->document();
+    Element* fullscreenElement = Fullscreen::currentFullScreenElementFrom(*document);
+    if (fullscreenElement)
+        document->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::FullScreen));

[esprehn, 2015/09/24 20:17:02]

This recalc's the style of the entire full screen subtree every time we call
updateStyle(), that seems bad. All you're trying to do is run that StyleAdjuster
code again? Is LocalStyleChange not enough?

Also lets do this with an API inside Fullscreen, not in web/

[dsinclair, 2015/09/28 17:14:58]

Done.

 }
 
 void FullscreenController::updatePageScaleConstraints(bool removeConstraints)
 {
     PageScaleConstraints fullscreenConstraints;
     if (!removeConstraints) {
         fullscreenConstraints = PageScaleConstraints(1.0, 1.0, 1.0);
         fullscreenConstraints.layoutSize = IntSize(m_webViewImpl->size());
     }
     m_webViewImpl->pageScaleConstraintsSet().setFullscreenConstraints(fullscreenConstraints);
     m_webViewImpl->pageScaleConstraintsSet().computeFinalConstraints();
     m_webViewImpl->updateMainFrameLayoutSize();
 }
 
 DEFINE_TRACE(FullscreenController)
 {
     visitor->trace(m_provisionalFullScreenElement);
     visitor->trace(m_fullScreenFrame);
 }
 
 } // namespace blink