Reset to initial page scale in additional scenarios.

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 2985 matching lines @@
     if (!settings()->viewportEnabled() || !page() || !m_size.width || !m_size.height)
         return;
 
     ViewportDescription adjustedDescription = description;
     if (settingsImpl()->viewportMetaLayoutSizeQuirk() && adjustedDescription.type == ViewportDescription::ViewportMeta) {
         if (adjustedDescription.maxWidth.type() == ExtendToZoom)
             adjustedDescription.maxWidth = Length(); // auto
         adjustedDescription.minWidth = adjustedDescription.maxWidth;
         adjustedDescription.minHeight = adjustedDescription.maxHeight;
     }
+    float oldInitialScale = m_pageScaleConstraintsSet.pageDefinedConstraints().initialScale;
     m_pageScaleConstraintsSet.updatePageDefinedConstraints(adjustedDescription, m_size);
     m_pageScaleConstraintsSet.adjustForAndroidWebViewQuirks(adjustedDescription, m_size, page()->settings().layoutFallbackWidth(), deviceScaleFactor(), settingsImpl()->supportDeprecatedTargetDensityDPI(), page()->settings().wideViewportQuirkEnabled(), page()->settings().useWideViewport(), page()->settings().loadWithOverviewMode());
+    float newInitialScale = m_pageScaleConstraintsSet.pageDefinedConstraints().initialScale;
+    if (oldInitialScale != newInitialScale && newInitialScale != -1) {
+        m_pageScaleConstraintsSet.setNeedsReset(true);
+        if (mainFrameImpl() && mainFrameImpl()->frameView())

[mnaganov (inactive), 2013/11/04 11:44:09]

I guess, we will have to cherry pick this 'if' into KK.

+            mainFrameImpl()->frameView()->setNeedsLayout();
+    }
 
     updateMainFrameLayoutSize();
 }
 
 void WebViewImpl::updateMainFrameLayoutSize()
 {
     if (m_fixedLayoutSizeLock || !mainFrameImpl())
         return;
 
     FrameView* view = mainFrameImpl()->frameView();
@@ skipping 1152 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace WebKit