Upstream service worker registration tests to WPT
The test for `getRegistration` in Chromium is identical to the
corresponding test in the Web Platform Tests project and may therefore
be removed.
The test for `getRegistrations` is likewise highly similar.
Schedule iframe removal to consistently occur following
sub-test completion (regardless of test results).
BUG=688116, 658997
R=mek@chromium.org
Review-Url: https://codereview.chromium.org/2853383004
Cr-Commit-Position: refs/heads/master@{#469071}
4 files changed
