FrameView's size should be calculated based on contentWidth+scrollbarWidth

Source/web/PageScaleConstraintsSet.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 124 matching lines @@
 
 void PageScaleConstraintsSet::didChangeViewSize(const IntSize& size)
 {
     if (m_viewSize == size)
         return;
 
     m_viewSize = size;
     m_constraintsDirty = true;
 }
 
-IntSize PageScaleConstraintsSet::mainFrameSize(const IntSize& contentsSize) const
+IntSize PageScaleConstraintsSet::mainFrameSize(int contentWidthIncludingScrollbar) const
 {
     // If there's no explicit minimum scale factor set, size the frame so that its width == content width
     // so there's no horizontal scrolling at the minimum scale.
     if (m_pageDefinedConstraints.minimumScale < finalConstraints().minimumScale
         && m_userAgentConstraints.minimumScale < finalConstraints().minimumScale
-        && contentsSize.width()
+        && contentWidthIncludingScrollbar
         && m_viewSize.width()) {
-        return expandedIntSize(FloatSize(contentsSize.width(), computeHeightByAspectRatio(contentsSize.width(), m_viewSize)));
+        return expandedIntSize(FloatSize(
+            contentWidthIncludingScrollbar,
+            computeHeightByAspectRatio(contentWidthIncludingScrollbar, m_viewSize)));
     }
 
     // If there is a minimum scale (or there's no content size yet), the frame size should match the viewport
     // size at minimum scale, since the viewport must always be contained by the frame.
     FloatSize frameSize(m_viewSize);
     frameSize.scale(1 / finalConstraints().minimumScale);
     return expandedIntSize(frameSize);
 }
 
 void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
@@ skipping 63 matching lines @@
             adjustedLayoutSizeWidth = m_viewSize.width() / targetDensityDPIFactor;
             adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
         }
     }
 
     m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
     m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
 }
 
 } // namespace blink