Rewrite test in terms of promise rejection

Rewrite test in terms of promise rejection

This patch rewrites animation-finish-event-cancelled.html to listen for
rejection of the animation's finished promise instead of using a combination
of onfinish and assertions about code being unreached. This makes the test
easier to read and brings it more in line with the style of tests in the
web-platform-tests suite.

BUG=623437
Committed: https://crrev.com/d8a910760e0c33dc93b4751e330b729936a1df5c
Cr-Commit-Position: refs/heads/master@{#405384}

[suzyh_UTC10 (ex-contributor), 2016-07-14 00:04:09]

suzyh@chromium.org changed reviewers:
+ alancutter@chromium.org

[suzyh_UTC10 (ex-contributor), 2016-07-14 00:04:13]

The CQ bit was checked by suzyh@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-14 00:05:06]

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

[alancutter (OOO until 2018), 2016-07-14 00:52:04]

lgtm

[alancutter (OOO until 2018), 2016-07-14 00:52:11]

The CQ bit was unchecked by alancutter@chromium.org

[alancutter (OOO until 2018), 2016-07-14 00:52:15]

The CQ bit was checked by alancutter@chromium.org

[commit-bot: I haz the power, 2016-07-14 00:52:54]

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, 2016-07-14 01:22:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-14 01:22:47]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-07-14 01:25:31]

Description was changed from

==========
Rewrite test in terms of promise rejection

This patch rewrites animation-finish-event-cancelled.html to listen for
rejection of the animation's finished promise instead of using a combination
of onfinish and assertions about code being unreached. This makes the test
easier to read and brings it more in line with the style of tests in the
web-platform-tests suite.

BUG=623437
==========

to

==========
Rewrite test in terms of promise rejection

This patch rewrites animation-finish-event-cancelled.html to listen for
rejection of the animation's finished promise instead of using a combination
of onfinish and assertions about code being unreached. This makes the test
easier to read and brings it more in line with the style of tests in the
web-platform-tests suite.

BUG=623437

Committed: https://crrev.com/d8a910760e0c33dc93b4751e330b729936a1df5c
Cr-Commit-Position: refs/heads/master@{#405384}
==========

[commit-bot: I haz the power, 2016-07-14 01:25:32]

Patchset 1 (id:??) landed as
https://crrev.com/d8a910760e0c33dc93b4751e330b729936a1df5c
Cr-Commit-Position: refs/heads/master@{#405384}