Avoid WTF::Vector::at() and operator[] in core/events.

Avoid WTF::Vector::at() and operator[] in core/events.

at() and operator[] are slow due to RELEASE_ASSERT. We can avoid the slowness by
range-based |for|.

This CL has no behavior changes except runtime performance.

BUG=668300
Committed: https://crrev.com/3ef1f1798c1964f6f20b009971ee843b1ab02bc3
Cr-Commit-Position: refs/heads/master@{#437083}

[tkent, 2016-12-07 06:29:12]

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

[commit-bot: I haz the power, 2016-12-07 06:29:22]

Dry run: 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, 2016-12-07 08:06:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-07 08:06:20]

Dry run: This issue passed the CQ dry run.

[tkent, 2016-12-07 08:38:11]

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

[commit-bot: I haz the power, 2016-12-07 08:38:28]

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

[tkent, 2016-12-07 08:46:53]

Patchset #1 (id:1) has been deleted

[tkent, 2016-12-07 08:48:22]

tkent@chromium.org changed reviewers:
+ hayato@chromium.org

[tkent, 2016-12-07 08:48:23]

hayato@, would you review this please?

[hayato, 2016-12-07 09:25:37]

lgtm

[commit-bot: I haz the power, 2016-12-07 10:19:28]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-07 10:19:29]

Dry run: This issue passed the CQ dry run.

[tkent, 2016-12-07 21:55:07]

The CQ bit was checked by tkent@chromium.org

[commit-bot: I haz the power, 2016-12-07 21:55:52]

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, 2016-12-07 22:17:59]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1481147707279130,
"parent_rev": "8070a3d97d43a66a3ee7feba47b9c7bb31b48ae5", "commit_rev":
"2e9a891869d7079ba3e6eaea4e7b1637e31b866e"}

[commit-bot: I haz the power, 2016-12-07 22:18:24]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2016-12-07 22:22:12]

Description was changed from

==========
Avoid WTF::Vector::at() and operator[] in core/events.

at() and operator[] are slow due to RELEASE_ASSERT. We can avoid the slowness by
range-based |for|.

This CL has no behavior changes except runtime performance.

BUG=668300
==========

to

==========
Avoid WTF::Vector::at() and operator[] in core/events.

at() and operator[] are slow due to RELEASE_ASSERT. We can avoid the slowness by
range-based |for|.

This CL has no behavior changes except runtime performance.

BUG=668300

Committed: https://crrev.com/3ef1f1798c1964f6f20b009971ee843b1ab02bc3
Cr-Commit-Position: refs/heads/master@{#437083}
==========

[commit-bot: I haz the power, 2016-12-07 22:22:13]

Patchset 1 (id:??) landed as
https://crrev.com/3ef1f1798c1964f6f20b009971ee843b1ab02bc3
Cr-Commit-Position: refs/heads/master@{#437083}