Optimize flattening of cons strings with equal left and right-side.

Optimize flattening of cons strings with equal left and right-side.

This significantly speeds up flattening repeat strings (e.g., '.'.repeat(1000)).

BUG=

Committed: https://crrev.com/4ebd97b42637d14292751f55143c1d98763106d4
Cr-Commit-Position: refs/heads/master@{#34751}

[Toon Verwaest, 2016-03-14 15:47:46]

verwaest@chromium.org changed reviewers:
+ yangguo@chromium.org

[Toon Verwaest, 2016-03-14 15:47:47]

ptal

[Yang, 2016-03-14 15:50:15]

lgtm. nice!

[Toon Verwaest, 2016-03-14 15:56:38]

The CQ bit was checked by verwaest@chromium.org

[commit-bot: I haz the power, 2016-03-14 15:56:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1798073002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1798073002/1

[commit-bot: I haz the power, 2016-03-14 16:19:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-14 16:20:34]

Description was changed from

==========
Optimize flattening of cons strings with equal left and right-side.

This significantly speeds up flattening repeat strings (e.g., '.'.repeat(1000)).

BUG=
==========

to

==========
Optimize flattening of cons strings with equal left and right-side.

This significantly speeds up flattening repeat strings (e.g., '.'.repeat(1000)).

BUG=

Committed: https://crrev.com/4ebd97b42637d14292751f55143c1d98763106d4
Cr-Commit-Position: refs/heads/master@{#34751}
==========

[commit-bot: I haz the power, 2016-03-14 16:20:35]

Patchset 1 (id:??) landed as
https://crrev.com/4ebd97b42637d14292751f55143c1d98763106d4
Cr-Commit-Position: refs/heads/master@{#34751}