Make targetDensity-dpi account for deviceScaleFactor correctly.

Source/core/page/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 93 matching lines @@
 
     float targetDPI = -1.0f;
     if (arguments.deprecatedTargetDensityDPI == ViewportArguments::ValueLowDPI)
         targetDPI = 120.0f;
     else if (arguments.deprecatedTargetDensityDPI == ViewportArguments::ValueMediumDPI)
         targetDPI = 160.0f;
     else if (arguments.deprecatedTargetDensityDPI == ViewportArguments::ValueHighDPI)
         targetDPI = 240.0f;
     else if (arguments.deprecatedTargetDensityDPI != ViewportArguments::ValueAuto)
         targetDPI = arguments.deprecatedTargetDensityDPI;
-    return targetDPI > 0 ? (deviceScaleFactor * 120.0f) / targetDPI : 1.0f;
+    // Since the return value is multiplied by deviceScaleFactor and deviceScaleFactor is displayDPI / 160.0 the below expands to:

[aelias_OOO_until_Jul13, 2013/08/08 18:34:37]

I suggest deleting this comment, I find it more distracting than enlightening.

[mkosiba (inactive), 2013/08/09 09:35:25]

Done.

+    // (160.0f / targetDPI) * (displayDPI / 160.0f) which is the same as displayDPI / targetDPI, which is what we want to determine.
+    return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
 }
 
 static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
 {
     return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
 }
 
 void PageScaleConstraintsSet::adjustPageDefinedConstraintsForAndroidWebView(const ViewportArguments& arguments, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool useWideViewport, bool loadWithOverviewMode)
 {
     float initialScale = m_pageDefinedConstraints.initialScale;
@@ skipping 18 matching lines @@
             adjustedLayoutSizeWidth /= targetDensityDPIFactor;
     }
 
     ASSERT(m_pageDefinedConstraints.layoutSize.width() > 0);
     float adjustedLayoutSizeHeight = (adjustedLayoutSizeWidth * m_pageDefinedConstraints.layoutSize.height()) / m_pageDefinedConstraints.layoutSize.width();
     m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
     m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
 }
 
 } // namespace WebCore