Replace Element::isMediaElement() with isHTMLMediaElement

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 70 matching lines @@
             if (!m_exitFullscreenPageScaleFactor) {
                 m_exitFullscreenPageScaleFactor = m_webViewImpl->pageScaleFactor();
                 m_exitFullscreenScrollOffset = m_webViewImpl->mainFrame()->scrollOffset();
                 m_webViewImpl->setPageScaleFactorPreservingScrollOffset(1.0f);
             }
 
             FullscreenElementStack::from(*doc).webkitDidEnterFullScreenForElement(0);
             if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()) {
                 Element* element = FullscreenElementStack::currentFullScreenElementFrom(*doc);
                 ASSERT(element);
-                if (element->isMediaElement() && m_webViewImpl->layerTreeView())
+                if (isHTMLMediaElement(*element) && m_webViewImpl->layerTreeView())
                     m_webViewImpl->layerTreeView()->setHasTransparentBackground(true);
             }
         }
     }
 }
 
 void FullscreenController::willExitFullScreen()
 {
     if (!m_fullScreenFrame)
         return;
@@ skipping 48 matching lines @@
 
     // We are already in fullscreen mode.
     if (m_fullScreenFrame) {
         m_provisionalFullScreenElement = element;
         willEnterFullScreen();
         didEnterFullScreen();
         return;
     }
 
     if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()
-        && element && element->isMediaElement()
+        && isHTMLMediaElement(element)
         // FIXME: There is no embedder-side handling in layout test mode.
         && !isRunningLayoutTest()) {
         HTMLMediaElement* mediaElement = toHTMLMediaElement(element);
         if (mediaElement->player() && mediaElement->player()->canShowFullscreenOverlay()) {
             mediaElement->player()->showFullscreenOverlay();
             m_provisionalFullScreenElement = element;
             return;
         }
     }
 
     // We need to transition to fullscreen mode.
     if (WebViewClient* client = m_webViewImpl->client()) {
         if (client->enterFullScreen())
             m_provisionalFullScreenElement = element;
     }
 }
 
 void FullscreenController::exitFullScreenForElement(WebCore::Element* element)
 {
     // The client is exiting full screen, so don't send a notification.
     if (m_isCancelingFullScreen)
         return;
     if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()
-        && element && element->isMediaElement()
+        && isHTMLMediaElement(element)
         // FIXME: There is no embedder-side handling in layout test mode.
         && !isRunningLayoutTest()) {
         HTMLMediaElement* mediaElement = toHTMLMediaElement(element);
         if (mediaElement->player())
             mediaElement->player()->hideFullscreenOverlay();
         return;
     }
     if (WebViewClient* client = m_webViewImpl->client())
         client->exitFullScreen();
 }
 
 }