Merge "Improve performance of SELECT element by optimizing Vector." to M52

Merge "Improve performance of SELECT element by optimizing Vector." to M52

Replace Vector::clear() with Vector::resize(0) to avoid to deallocate Vector
buffers.

Removing 20,000 OPTIONs: 7,595ms -> 5,779ms

BUG=624220
Review-Url: https://codereview.chromium.org/2105863003
Cr-Commit-Position: refs/heads/master@{#402720}
(cherry picked from commit 8881397e890dd70a187a957ae6910f141d378eb5)

Committed: https://chromium.googlesource.com/chromium/src/+/4477cc6040e3ebc7300c372a8d58fab20c96eb59

[tkent, 2016-07-01 05:46:33]

Description was changed from

==========
Merge "Improve performance of SELECT element by optimizing Vector." to M52

Replace Vector::clear() with Vector::resize(0) to avoid to deallocate Vector
buffers.

Removing 20,000 OPTIONs: 7,595ms -> 5,779ms

BUG=624220

Review-Url: https://codereview.chromium.org/2105863003
Cr-Commit-Position: refs/heads/master@{#402720}
(cherry picked from commit 8881397e890dd70a187a957ae6910f141d378eb5)
==========

to

==========
Merge "Improve performance of SELECT element by optimizing Vector." to M52

Replace Vector::clear() with Vector::resize(0) to avoid to deallocate Vector
buffers.

Removing 20,000 OPTIONs: 7,595ms -> 5,779ms

BUG=624220

Review-Url: https://codereview.chromium.org/2105863003
Cr-Commit-Position: refs/heads/master@{#402720}
(cherry picked from commit 8881397e890dd70a187a957ae6910f141d378eb5)

Committed:
https://chromium.googlesource.com/chromium/src/+/4477cc6040e3ebc7300c372a8d58...
==========

[tkent, 2016-07-01 05:46:35]

Committed patchset #1 (id:1) manually as
4477cc6040e3ebc7300c372a8d58fab20c96eb59.