Worker: Import "imported/wpt/workers" tests (Retry)

The original CL was reverted because the test expectations didn't contain some
failing tests. This CL imports the tests again with the updated test
expectations.

Original CL: https://codereview.chromium.org/2405143002/

BUG=651778, 655458

Review-Url: https://codereview.chromium.org/2418853003
Cr-Commit-Position: refs/heads/master@{#425251}
236 files changed