Clarify fullscreenElement vs. currentFullScreenElement distinction

third_party/WebKit/Source/web/WebPluginContainerImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. 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.
@@ skipping 303 matching lines @@
         m_element->setNeedsCompositingUpdate();
 }
 
 void WebPluginContainerImpl::requestFullscreen()
 {
     Fullscreen::from(m_element->document()).requestFullscreen(*m_element, Fullscreen::PrefixedRequest);
 }
 
 bool WebPluginContainerImpl::isFullscreenElement() const
 {
-    if (Fullscreen* fullscreen = Fullscreen::fromIfExists(m_element->document()))
-        return m_element == fullscreen->webkitCurrentFullScreenElement();
-    return false;
+    return Fullscreen::isCurrentFullScreenElement(*m_element);
 }
 
 void WebPluginContainerImpl::cancelFullscreen()
 {
     Fullscreen::fullyExitFullscreen(m_element->document());
 }
 
 bool WebPluginContainerImpl::supportsPaginatedPrint() const
 {
     return m_webPlugin->supportsPaginatedPrint();
@@ skipping 602 matching lines @@
         // frame view.
         computeClipRectsForPlugin(m_element, windowRect, clipRect, unobscuredRect);
     }
     getPluginOcclusions(m_element, this->parent(), frameRect(), cutOutRects);
     // Convert to the plugin position.
     for (size_t i = 0; i < cutOutRects.size(); i++)
         cutOutRects[i].move(-frameRect().x(), -frameRect().y());
 }
 
 } // namespace blink