[Android WebView] Avoid expanding layout width to match the old WebView

Source/core/page/PageScaleConstraintsSet.cpp

Index: Source/core/page/PageScaleConstraintsSet.cpp
diff --git a/Source/core/page/PageScaleConstraintsSet.cpp b/Source/core/page/PageScaleConstraintsSet.cpp
index e0d185b6542fa03e2a6d47f5e0a90ac81d340dab..347af42be0f040e581fed34631187efb139e8c84 100644
--- a/Source/core/page/PageScaleConstraintsSet.cpp
+++ b/Source/core/page/PageScaleConstraintsSet.cpp
@@ -136,9 +136,13 @@ void PageScaleConstraintsSet::adjustPageDefinedConstraintsForAndroidWebView(cons
     float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
     if (useWideViewport && arguments.width == -1 && arguments.zoom != 1.0f)
         adjustedLayoutSizeWidth = layoutFallbackWidth;
+    else if (useWideViewport && arguments.width != -1 && arguments.width != ViewportArguments::ValueDeviceWidth)
+        adjustedLayoutSizeWidth = arguments.width;

[aelias_OOO_until_Jul13, 2013/08/21 20:23:54]

This ends up bypassing every other width computation in ViewportArguments, for
example min-width.  It looks like the only way to do make the behavior change as
narrow as we want is via a parameter used by ViewportArguments::resolve().  

I suggest adding a new enum value to ViewportArguments::resolve,
ViewportMetaSupportingTargetDensityDpi.  Change arguments.type to that in
WebViewImpl::updatePageDefinedPageScaleConstraints by making a local copy of the
object.  Then ViewportArguments::resolve() will already do the right thing
without any further changes (because CSS-device-adaptation standard doesn't want
the weird initial-scale behavior of Safari either).

[mnaganov (inactive), 2013/08/22 08:51:55]

Thanks for the suggestion, Alexandre! I didn't consider adding a new
ViewportArguments type, thinking only of adding an extra argument to ::resolve,
which seemed too ugly, so I resorted to post-patching the value. You approach is
much more creative!

     else {
         if (!useWideViewport)
             adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(viewSize, initialScale);
+        else if (arguments.width == ViewportArguments::ValueDeviceWidth || (arguments.width == -1 && arguments.zoom == 1.0f))
+            adjustedLayoutSizeWidth = viewSize.width();
         if (!useWideViewport || arguments.width == -1 || arguments.width == ViewportArguments::ValueDeviceWidth)
             adjustedLayoutSizeWidth /= targetDensityDPIFactor;
     }