Mainly changes the behaviour of WebViewImpl::animateZoomAroundPoint to take a rect instead and handling an additional zoom type to zoom in on the specified rect and returning false if it doesn't zoom. (if it would be a zoom-out)

Related review: https://codereview.chromium.org/19256012/

BUG=260644

Review URL: https://chromiumcodereview.appspot.com/19281007

git-svn-id: svn://svn.chromium.org/blink/trunk@155243 bbb929c8-8fbe-4397-9dbb-9b2b20218538