[Android WebView] Add a settings to disallow initializing background-size if background shorthand doesn't include it

Re-applied patch from WK https://bugs.webkit.org/show_bug.cgi?id=113363 to
support legacy applications using Android WebView.

BUG=277157

Review URL: https://chromiumcodereview.appspot.com/23264037

git-svn-id: svn://svn.chromium.org/blink/trunk@156632 bbb929c8-8fbe-4397-9dbb-9b2b20218538