StyleInvalidationAnalysis cannot use selector scope for ^ and ^^ rules.

TEST=fast/dom/shadow/dynamically-added-cat-hat-rules.html
BUG=339657

Review URL: https://codereview.chromium.org/136643004

git-svn-id: svn://svn.chromium.org/blink/trunk@166556 bbb929c8-8fbe-4397-9dbb-9b2b20218538