Remove extraneous SubtreeStyleChange for min/maxlength changes.

Remove extraneous SubtreeStyleChange for min/maxlength changes.

Validation already takes care of :valid/:invalid changes through
invalidation sets. This reduces the number of elements being recalculated
and gets rid of a SubtreeStyleChange which relies on sibling tree recalcs.

R=tkent@chromium.org
BUG=557440
Committed: https://crrev.com/81fb8abcd74847f62bf89e45e6dda0c7464e08c4
Cr-Commit-Position: refs/heads/master@{#361123}

[rune, 2015-11-20 13:32:42]

The CQ bit was checked by rune@opera.com to run a CQ dry run

[rune, 2015-11-20 13:32:51]

ptal

[commit-bot: I haz the power, 2015-11-20 13:33:25]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1458363003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1458363003/1

[commit-bot: I haz the power, 2015-11-20 14:45:53]

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

[commit-bot: I haz the power, 2015-11-20 14:45:54]

Dry run: This issue passed the CQ dry run.

[tkent, 2015-11-23 14:44:30]

lgtm

[rune, 2015-11-23 14:50:17]

The CQ bit was checked by rune@opera.com

[commit-bot: I haz the power, 2015-11-23 14:50:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1458363003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1458363003/1

[commit-bot: I haz the power, 2015-11-23 16:30:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-23 16:31:13]

Patchset 1 (id:??) landed as
https://crrev.com/81fb8abcd74847f62bf89e45e6dda0c7464e08c4
Cr-Commit-Position: refs/heads/master@{#361123}