[Push API] Fix flaky PushEventNotificationWithoutEventWaitUntil

[Push API] Fix flaky PushEventNotificationWithoutEventWaitUntil

PushMessagingBrowserTest.PushEventNotificationWithoutEventWaitUntil
was flaking occasionally with the final
EXPECT_TRUE(IsRegisteredKeepAliveEqualTo(false)); evaluating to false.

This was because the test's MessageLoopRunner was quitting once
the notification was shown, and the test was assuming that the push
message delivery would have finished by this point, but in reality
these two events race against each other.

This patch fixes the test to wait until both required events finish.

BUG=none

Review-Url: https://codereview.chromium.org/2781413002
Cr-Commit-Position: refs/heads/master@{#461002}
Committed: https://chromium.googlesource.com/chromium/src/+/bd8ddbe23babcdf02ecd0fc9efe85023e92dff4d

[johnme, 2017-03-30 16:06:51]

johnme@chromium.org changed reviewers:
+ peter@chromium.org

[Peter Beverloo, 2017-03-31 00:40:40]

lgtm

[johnme, 2017-03-31 01:40:50]

The CQ bit was checked by johnme@chromium.org

[commit-bot: I haz the power, 2017-03-31 01:41:32]

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, 2017-03-31 02:36:06]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490924450794570, "parent_rev":
"97a6cd07bba4da3053a08fc7d06d35678588e054", "commit_rev":
"bd8ddbe23babcdf02ecd0fc9efe85023e92dff4d"}

[commit-bot: I haz the power, 2017-03-31 02:36:55]

Description was changed from

==========
[Push API] Fix flaky PushEventNotificationWithoutEventWaitUntil

PushMessagingBrowserTest.PushEventNotificationWithoutEventWaitUntil
was flaking occasionally with the final
EXPECT_TRUE(IsRegisteredKeepAliveEqualTo(false)); evaluating to false.

This was because the test's MessageLoopRunner was quitting once
the notification was shown, and the test was assuming that the push
message delivery would have finished by this point, but in reality
these two events race against each other.

This patch fixes the test to wait until both required events finish.

BUG=none
==========

to

==========
[Push API] Fix flaky PushEventNotificationWithoutEventWaitUntil

PushMessagingBrowserTest.PushEventNotificationWithoutEventWaitUntil
was flaking occasionally with the final
EXPECT_TRUE(IsRegisteredKeepAliveEqualTo(false)); evaluating to false.

This was because the test's MessageLoopRunner was quitting once
the notification was shown, and the test was assuming that the push
message delivery would have finished by this point, but in reality
these two events race against each other.

This patch fixes the test to wait until both required events finish.

BUG=none

Review-Url: https://codereview.chromium.org/2781413002
Cr-Commit-Position: refs/heads/master@{#461002}
Committed:
https://chromium.googlesource.com/chromium/src/+/bd8ddbe23babcdf02ecd0fc9efe8...
==========

[commit-bot: I haz the power, 2017-03-31 02:36:56]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/bd8ddbe23babcdf02ecd0fc9efe8...