Corrected serialization of ::cue() functions.

The selectorList argument of ::cue() functions were just dropped.
Serialization of that list is now done.

The explicit universal tag "*" is not correct per CSSOM spec, but I didn't
address that in this CL. Besides, that also affects a bunch of the custom
pseudo elements. Nothing changed here.

Also removed a bunch of unnecessary CSSSelector:: prefixing.

R=timloh@chromium.org,andersr@opera.com
BUG=428696

Review URL: https://codereview.chromium.org/689933002

git-svn-id: svn://svn.chromium.org/blink/trunk@184767 bbb929c8-8fbe-4397-9dbb-9b2b20218538