[cherry-pick] Use contents size for android_webview layout size.
This is a cherry-pick of http://crrev.com/23899004
> Currently android_webview uses RenderView::preferredSize (which is
> based off of documentElement.height) to drive the android.view.View
> layout size.
> WebViewClassic would use content size for that purpose which meant
> that absolute-positioned elements can cause the Classic WebView to
> grow.
> This CL makes AwContents use the contents size for driving layout.
>
> BUG=286336
BUG: 10635059
Change-Id: I7efc9e6960dbbfcf00e7a62d837135d6911dc993
19 files changed
