[Android WebView] Add a quirk to clobber initial scale in certain cases

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 111 matching lines @@
     else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
         targetDPI = description.deprecatedTargetDensityDPI;
     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::adjustForAndroidWebViewQuirks(const ViewportDescription& description, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode)
+void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool clobberUserAgentInitialScaleQuirk)
 {
-    if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode)
+    if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !clobberUserAgentInitialScaleQuirk)
         return;
 
     const float oldInitialScale = m_pageDefinedConstraints.initialScale;
     if (!loadWithOverviewMode) {
         bool resetInitialScale = false;
         if (description.zoom == -1) {
             if (description.maxWidth.isAuto())
                 resetInitialScale = true;
             if (useWideViewport || !description.maxWidth.isFixed())
                 resetInitialScale = true;
         }
         if (resetInitialScale)
             m_pageDefinedConstraints.initialScale = 1.0f;
     }
 
     float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
     float targetDensityDPIFactor = 1.0f;
 
     if (supportTargetDensityDPI) {
         targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
         if (m_pageDefinedConstraints.initialScale != -1)
             m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
         m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
         m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
         if (wideViewportQuirkEnabled && (!useWideViewport || !description.maxWidth.isFixed()))
             adjustedLayoutSizeWidth /= targetDensityDPIFactor;
     }
 
+    if (clobberUserAgentInitialScaleQuirk && m_userAgentConstraints.initialScale * deviceScaleFactor <= 1.0f) {
+        if (!description.maxWidth.isFixed() || (description.maxWidth.isAuto() && oldInitialScale == 1.0f))
+            m_userAgentConstraints.initialScale = -1;
+    }
+
     if (wideViewportQuirkEnabled) {
         if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
             adjustedLayoutSizeWidth = layoutFallbackWidth;
         } else if (!useWideViewport) {
             const float nonWideScale = description.zoom < 1 && !description.maxWidth.isViewportPercentage() ? -1 : oldInitialScale;
             adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(viewSize, nonWideScale) / targetDensityDPIFactor;
             if (description.zoom < 1) {
                 m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
                 m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
                 m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
             }
         }
     }
 
     if (adjustedLayoutSizeWidth != m_pageDefinedConstraints.layoutSize.width()) {
         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