Break up with StyleResolveScope

This class doesn't exist any more so we don't need to be friends.

NOTRY=true
TBR=eseidel@chromium.org

Review URL: https://codereview.chromium.org/217603006

git-svn-id: svn://svn.chromium.org/blink/trunk@170394 bbb929c8-8fbe-4397-9dbb-9b2b20218538