Fix fullscreen media control position issue when switching orientation

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 65 matching lines @@
     if (!m_fullScreenFrame)
         return;
 
     if (Document* doc = m_fullScreenFrame->document()) {
         if (FullscreenElementStack::isFullScreen(*doc)) {
             if (!m_exitFullscreenPageScaleFactor) {
                 m_exitFullscreenPageScaleFactor = m_webViewImpl->pageScaleFactor();
                 m_exitFullscreenScrollOffset = m_webViewImpl->mainFrame()->scrollOffset();
                 m_exitFullscreenPinchViewportOffset = m_webViewImpl->pinchViewportOffset();
                 m_webViewImpl->setPageScaleFactor(1.0f);
+                m_webViewImpl->setMainFrameScrollOffset(IntPoint());
+                m_webViewImpl->setPinchViewportOffset(FloatPoint());
             }
 
             FullscreenElementStack::from(*doc).webkitDidEnterFullScreenForElement(0);
             if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled()) {
                 Element* element = FullscreenElementStack::currentFullScreenElementFrom(*doc);
                 ASSERT(element);
                 if (isHTMLMediaElement(*element) && m_webViewImpl->layerTreeView())
                     m_webViewImpl->layerTreeView()->setHasTransparentBackground(true);
             }
         }
@@ skipping 94 matching lines @@
         if (mediaElement->webMediaPlayer())
             mediaElement->webMediaPlayer()->exitFullscreen();
         return;
     }
     if (WebViewClient* client = m_webViewImpl->client())
         client->exitFullScreen();
 }
 
 }