Upstream service worker postMessage tests to WPT

Upstream service worker postMessage tests to WPT

BUG=688116
R=falken@chromium.org

Review-Url: https://codereview.chromium.org/2763113002
Cr-Commit-Position: refs/heads/master@{#458941}
Committed: https://chromium.googlesource.com/chromium/src/+/4f03d873326c61514cea9f4b4f293c43a7327b76

[mike3, 2017-03-21 18:44:14]

@falken Some of the tests in `ServiceWorkerGlobalScope` rely on global state,
making them potentially flaky. There are already a fair number of tests in WPT
that suffer from this problem, but I'd still like to resolve that upstream
before migrating those into place.

I've started a conversation along these lines here:

https://github.com/w3c/ServiceWorker/issues/1087

Because I'm trying to keep each submission organized conceptually, this patch
is very small--only one test within `ServiceWorkerGlobalScope` directory.
Here's the full diff (generated use `git diff`'s `-M10` flag):

https://gist.github.com/jugglinmike/7716ba78a21c9d425468d66844206e27

[falken, 2017-03-22 13:29:26]

lgtm

small patches are very welcome :)

[mike3, 2017-03-22 22:32:55]

The CQ bit was checked by mike@mikepennisi.com

[commit-bot: I haz the power, 2017-03-22 22:34:14]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-23 00:07:59]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490221975563290, "parent_rev":
"6cf1f32a1b57b5f3018cab99820f6f8a4c0270f9", "commit_rev":
"4f03d873326c61514cea9f4b4f293c43a7327b76"}

[commit-bot: I haz the power, 2017-03-23 00:08:52]

Description was changed from

==========
Upstream service worker postMessage tests to WPT

BUG=688116
R=falken@chromium.org
==========

to

==========
Upstream service worker postMessage tests to WPT

BUG=688116
R=falken@chromium.org

Review-Url: https://codereview.chromium.org/2763113002
Cr-Commit-Position: refs/heads/master@{#458941}
Committed:
https://chromium.googlesource.com/chromium/src/+/4f03d873326c61514cea9f4b4f29...
==========

[commit-bot: I haz the power, 2017-03-23 00:08:53]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/4f03d873326c61514cea9f4b4f29...