Only have drawsContent() be true for graphics layers if not paintsIntoCompositedAncestor.

BUG=409593

Review URL: https://codereview.chromium.org/568903002

git-svn-id: svn://svn.chromium.org/blink/trunk@181943 bbb929c8-8fbe-4397-9dbb-9b2b20218538