Reset VisualViewport position after same page navigation

third_party/WebKit/Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 418 matching lines @@
 
 void Page::didCommitLoad(LocalFrame* frame)
 {
     if (m_mainFrame == frame) {
         // TODO(rbyers): Most of this doesn't appear to take into account that each
         // SVGImage gets it's own Page instance.
         frameHost().consoleMessageStorage().clear();
         useCounter().didCommitLoad();
         deprecation().clearSuppression();
         frameHost().visualViewport().sendUMAMetrics();
+
+        // Need to reset visual viewport position here since before commit load we would update the previous history item,
+        // Page::didCommitLoad is called after a new history item is created in FrameLoader.
+        // fix for crbug.com/642279
+        frameHost().visualViewport().setScrollPosition(DoublePoint(), ProgrammaticScroll);
         m_hostsUsingFeatures.updateMeasurementsAndClear();
         UserGestureIndicator::clearProcessedUserGestureSinceLoad();
     }
 }
 
 void Page::acceptLanguagesChanged()
 {
     HeapVector<Member<LocalFrame>> frames;
 
     // Even though we don't fire an event from here, the LocalDOMWindow's will fire
@@ skipping 71 matching lines @@
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 template class CORE_TEMPLATE_EXPORT Supplement<Page>;
 
 } // namespace blink