Page load metrics: improve flaky CSSTiming

Page load metrics: improve flaky CSSTiming

Make CSSTiming less flaky by waiting for the style updated event.

BUG=697761
Review-Url: https://codereview.chromium.org/2729893002
Cr-Commit-Position: refs/heads/master@{#454553}
Committed: https://chromium.googlesource.com/chromium/src/+/dcdc81fcde2b5b40f42023a5bdb46e6c7c6b08ec

[mattcary, 2017-03-02 15:52:44]

mattcary@chromium.org changed reviewers:
+ bmcquade@chromium.org

[Charlie Harrison, 2017-03-02 16:22:19]

csharrison@chromium.org changed reviewers:
+ csharrison@chromium.org

[Charlie Harrison, 2017-03-02 16:22:19]

LGTM

[mattcary, 2017-03-03 09:17:36]

The CQ bit was checked by mattcary@chromium.org

[commit-bot: I haz the power, 2017-03-03 09:17:44]

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, 2017-03-03 09:52:58]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1488532656766730, "parent_rev":
"bee44e2b6c7a93b28e1082743784045447498476", "commit_rev":
"dcdc81fcde2b5b40f42023a5bdb46e6c7c6b08ec"}

[commit-bot: I haz the power, 2017-03-03 09:53:36]

Description was changed from

==========
Page load metrics: improve flaky CSSTiming

Make CSSTiming less flaky by waiting for the style updated event.

BUG=697761
==========

to

==========
Page load metrics: improve flaky CSSTiming

Make CSSTiming less flaky by waiting for the style updated event.

BUG=697761

Review-Url: https://codereview.chromium.org/2729893002
Cr-Commit-Position: refs/heads/master@{#454553}
Committed:
https://chromium.googlesource.com/chromium/src/+/dcdc81fcde2b5b40f42023a5bdb4...
==========

[commit-bot: I haz the power, 2017-03-03 09:53:37]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/dcdc81fcde2b5b40f42023a5bdb4...