Remove unneeded check in requestPaintingResource

The check is not needed because hasFill/hasStroke calls above check the same thing.

Review URL: https://codereview.chromium.org/197213009

git-svn-id: svn://svn.chromium.org/blink/trunk@169262 bbb929c8-8fbe-4397-9dbb-9b2b20218538