Triage few w3c/web-platform-tests/custom-elements/
Triage few w3c/web-platform-tests/custom-elements/

Point w3c/web-platform-tests/custom-elements/ failures to
appropriate bug.

Review URL: https://codereview.chromium.org/547383002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@181712 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs