Disable touch ack timeout if MT responsiveness scroll intervention on.

Disable touch ack timeout if MT responsiveness scroll intervention on.

If the main thread responsiveness scroll intervention is on, disable
the touch ack timeout. See the intent to implement for details:

https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/CGeXqTudllA/3t72vfXOBAAJ

BUG=599609
TEST=Manually tested locally.

Review-Url: https://codereview.chromium.org/2689633003
Cr-Commit-Position: refs/heads/master@{#449959}
Committed: https://chromium.googlesource.com/chromium/src/+/a1731fe3102fa6716917dc513a1725af7ce8dfa4

[tdresser, 2017-02-10 16:16:14]

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

[tdresser, 2017-02-10 16:16:15]

We'll launch this behind a finch trial.

There are rare cases where this is worse than the touch ack timeout - in
particular, cases where the main thread isn't busy at all except for event
handlers.

Even then we're worse at the very beginning (we block until the first event is
done being processed), but then we don't block scroll again until the main
thread quiesces, so if you're performing repeated scrolls with long event
handlers, the overall experience is better.

[aelias_OOO_until_Jul13, 2017-02-11 00:48:49]

lgtm

[tdresser, 2017-02-13 14:29:32]

The CQ bit was checked by tdresser@chromium.org

[commit-bot: I haz the power, 2017-02-13 14:29:49]

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, 2017-02-13 15:16:44]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1486996172688440, "parent_rev":
"5c6e9372daae557d6857f02888e84363eeff9be9", "commit_rev":
"a1731fe3102fa6716917dc513a1725af7ce8dfa4"}

[commit-bot: I haz the power, 2017-02-13 15:17:17]

Description was changed from

==========
Disable touch ack timeout if MT responsiveness scroll intervention on.

If the main thread responsiveness scroll intervention is on, disable
the touch ack timeout. See the intent to implement for details:

https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/CGeXqTudllA/3t...

BUG=599609
TEST=Manually tested locally.
==========

to

==========
Disable touch ack timeout if MT responsiveness scroll intervention on.

If the main thread responsiveness scroll intervention is on, disable
the touch ack timeout. See the intent to implement for details:

https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/CGeXqTudllA/3t...

BUG=599609
TEST=Manually tested locally.

Review-Url: https://codereview.chromium.org/2689633003
Cr-Commit-Position: refs/heads/master@{#449959}
Committed:
https://chromium.googlesource.com/chromium/src/+/a1731fe3102fa6716917dc513a17...
==========

[commit-bot: I haz the power, 2017-02-13 15:17:17]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/a1731fe3102fa6716917dc513a17...