[CSS Shapes] large corner radius combined with 0 radius does not wrap properly

Corrected special case handling for shape-outside border-box values with border-radius
values that greater than or equal to the box's height.

This is a merge of http://trac.webkit.org/changeset/166966 by Hans Muller <hmuller@adobe.com>.

BUG=361329

Review URL: https://codereview.chromium.org/230403003

git-svn-id: svn://svn.chromium.org/blink/trunk@171173 bbb929c8-8fbe-4397-9dbb-9b2b20218538