Fixing two layout tests on Android broken by enabling virtual-viewport

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 132 matching lines @@
 }
 
 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
         && contentWidthIncludingScrollbar
         && m_viewSize.width()) {
+
+        // Special case where the contents are exactly as wide as the viewport to prevent an off-by-one due
+        // to floating point imprecision in the aspect ratio height calculation.
+        if (contentWidthIncludingScrollbar == m_viewSize.width())
+            return 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);
@@ skipping 66 matching lines @@
             adjustedLayoutSizeWidth = m_viewSize.width() / targetDensityDPIFactor;
             adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
         }
     }
 
     m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
     m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
 }
 
 } // namespace blink