Fix race in ServiceWorkerBackgroundSyncTest.Sync

Fix race in ServiceWorkerBackgroundSyncTest.Sync

It's possible for the sync event to be dispatched in the test before
the postMessage is received by the ServiceWorker. This CL fixes that
by waiting for a response from the postMessage before starting the
sync event.

BUG=595191
Committed: https://crrev.com/37d4fa339120b2d98b41b4fc037d11131c12aac4
Cr-Commit-Position: refs/heads/master@{#381499}

[jkarlin, 2016-03-16 15:33:10]

jkarlin@chromium.org changed reviewers:
+ iclelland@chromium.org, lazyboy@chromium.org

[jkarlin, 2016-03-16 15:33:11]

PTAL, thanks!

[iclelland, 2016-03-16 15:46:33]

https://codereview.chromium.org/1812503002/diff/1/chrome/test/data/extensions...
File chrome/test/data/extensions/api_test/service_worker/sync/sw.js (right):

https://codereview.chromium.org/1812503002/diff/1/chrome/test/data/extensions...
chrome/test/data/extensions/api_test/service_worker/sync/sw.js:24:
port.postMessage('connected');
Should this check to see if e.data is "connect"? I don't know if there's ever
any *other* reason to postMessage to the service worker, but if we ever do, this
will echo back every time, and the page will end up triggering
SERVICE_WORKER_READY every time.

[jkarlin, 2016-03-16 16:59:37]

Thanks, PTAL

https://codereview.chromium.org/1812503002/diff/1/chrome/test/data/extensions...
File chrome/test/data/extensions/api_test/service_worker/sync/sw.js (right):

https://codereview.chromium.org/1812503002/diff/1/chrome/test/data/extensions...
chrome/test/data/extensions/api_test/service_worker/sync/sw.js:24:
port.postMessage('connected');
On 2016/03/16 15:46:33, iclelland wrote:
> Should this check to see if e.data is "connect"? I don't know if there's ever
> any *other* reason to postMessage to the service worker, but if we ever do,
this
> will echo back every time, and the page will end up triggering
> SERVICE_WORKER_READY every time.

Sure. Done.

[iclelland, 2016-03-16 17:46:09]

lgtm

[jkarlin, 2016-03-16 17:46:34]

The CQ bit was checked by jkarlin@chromium.org

[commit-bot: I haz the power, 2016-03-16 17:47:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1812503002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1812503002/20001

[lazyboy, 2016-03-16 17:55:34]

lgtm, thank you!

[commit-bot: I haz the power, 2016-03-16 18:17:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-16 18:19:19]

Description was changed from

==========
Fix race in ServiceWorkerBackgroundSyncTest.Sync

It's possible for the sync event to be dispatched in the test before
the postMessage is received by the ServiceWorker. This CL fixes that
by waiting for a response from the postMessage before starting the
sync event.

BUG=595191
==========

to

==========
Fix race in ServiceWorkerBackgroundSyncTest.Sync

It's possible for the sync event to be dispatched in the test before
the postMessage is received by the ServiceWorker. This CL fixes that
by waiting for a response from the postMessage before starting the
sync event.

BUG=595191

Committed: https://crrev.com/37d4fa339120b2d98b41b4fc037d11131c12aac4
Cr-Commit-Position: refs/heads/master@{#381499}
==========

[commit-bot: I haz the power, 2016-03-16 18:19:21]

Patchset 2 (id:??) landed as
https://crrev.com/37d4fa339120b2d98b41b4fc037d11131c12aac4
Cr-Commit-Position: refs/heads/master@{#381499}