Improve performance of HTMLElement::attributeChanged.

Improve performance of HTMLElement::attributeChanged.

Call adjustedFocusedElementInTreeScope() only if the modified attribute can
affect focusability.

BUG=677446
Review-Url: https://codereview.chromium.org/2625903002
Cr-Commit-Position: refs/heads/master@{#442794}
Committed: https://chromium.googlesource.com/chromium/src/+/ca7cf349eaf2714ed766e67827486b8417aa84b7

[tkent, 2017-01-11 00:24:42]

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

[commit-bot: I haz the power, 2017-01-11 00:25:37]

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

[tkent, 2017-01-11 00:25:40]

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

[tkent, 2017-01-11 00:25:40]

kochi@, would you review this please?

Dromaeo.domcoreattr on macOS, 780 runs/sec -> 850 runs/sec

[kochi, 2017-01-11 00:35:36]

lgtm

[commit-bot: I haz the power, 2017-01-11 01:50:33]

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

[commit-bot: I haz the power, 2017-01-11 01:50:34]

Dry run: Try jobs failed on following builders:
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)

[tkent, 2017-01-11 02:23:06]

The CQ bit was checked by tkent@chromium.org

[commit-bot: I haz the power, 2017-01-11 02:23:35]

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, 2017-01-11 04:13:16]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1484101386632860, "parent_rev":
"31a3f75562091491b6b0c2941a9c845407fb38c2", "commit_rev":
"ca7cf349eaf2714ed766e67827486b8417aa84b7"}

[commit-bot: I haz the power, 2017-01-11 04:13:52]

Description was changed from

==========
Improve performance of HTMLElement::attributeChanged.

Call adjustedFocusedElementInTreeScope() only if the modified attribute can
affect focusability.

BUG=677446
==========

to

==========
Improve performance of HTMLElement::attributeChanged.

Call adjustedFocusedElementInTreeScope() only if the modified attribute can
affect focusability.

BUG=677446

Review-Url: https://codereview.chromium.org/2625903002
Cr-Commit-Position: refs/heads/master@{#442794}
Committed:
https://chromium.googlesource.com/chromium/src/+/ca7cf349eaf2714ed766e6782748...
==========

[commit-bot: I haz the power, 2017-01-11 04:13:53]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/ca7cf349eaf2714ed766e6782748...