Fix Flaky Mouse latency test.

Fix Flaky Mouse latency test.

There are some timing issues that are tricky to get right for cases
where rendering is scheduled due to mouse input. Fix the flake by
preventing rendering from being scheduled.

Mouse down was triggering text selection logic, which scheduled
rendering. To prevent this, use user-select:none.

BUG=728486
Review-Url: https://codereview.chromium.org/2923623002
Cr-Commit-Position: refs/heads/master@{#477037}
Committed: https://chromium.googlesource.com/chromium/src/+/ecfb2ded05e975b139ea9929958b3b366c65f93e

[tdresser, 2017-06-05 17:50:56]

tdresser@chromium.org changed reviewers:
+ dtapuska@chromium.org

[tdresser, 2017-06-05 17:51:02]

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

[commit-bot: I haz the power, 2017-06-05 17:51:23]

Dry run: CQ is trying da patch.

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

[dtapuska, 2017-06-05 17:58:07]

On 2017/06/05 17:50:57, tdresser wrote:

lgtm

[tdresser, 2017-06-05 18:09:03]

The CQ bit was unchecked by tdresser@chromium.org

[tdresser, 2017-06-05 18:09:09]

The CQ bit was checked by tdresser@chromium.org

[commit-bot: I haz the power, 2017-06-05 18:09:15]

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, 2017-06-05 18:36:28]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1496686149695220,
"parent_rev": "445803df423a6d3aa10024ff89ce33e52817c547", "commit_rev":
"ecfb2ded05e975b139ea9929958b3b366c65f93e"}

[commit-bot: I haz the power, 2017-06-05 18:36:37]

Description was changed from

==========
Fix Flaky Mouse latency test.

There are some timing issues that are tricky to get right for cases
where rendering is scheduled due to mouse input. Fix the flake by
preventing rendering from being scheduled.

Mouse down was triggering text selection logic, which scheduled
rendering. To prevent this, use user-select:none.

BUG=728486
==========

to

==========
Fix Flaky Mouse latency test.

There are some timing issues that are tricky to get right for cases
where rendering is scheduled due to mouse input. Fix the flake by
preventing rendering from being scheduled.

Mouse down was triggering text selection logic, which scheduled
rendering. To prevent this, use user-select:none.

BUG=728486

Review-Url: https://codereview.chromium.org/2923623002
Cr-Commit-Position: refs/heads/master@{#477037}
Committed:
https://chromium.googlesource.com/chromium/src/+/ecfb2ded05e975b139ea9929958b...
==========

[commit-bot: I haz the power, 2017-06-05 18:36:41]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/ecfb2ded05e975b139ea9929958b...