changing std::vector to std::set for all_tiles_

changing std::vector to std::set for all_tiles_

This improves the performance of removing a tile from the list to O(log(n)) from O(n).  The O(n) removal time was showing up as lag spikes in a trace.

BUG=175939
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=182297

[ccameron, 2013-02-13 05:28:44]

lgtm

[commit-bot: I haz the power, 2013-02-13 05:29:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/whunt@chromium.org/12207146/1

[commit-bot: I haz the power, 2013-02-13 05:51:55]

Sorry for I got bad news for ya.
Compile failed with a clobber build on android_clang_dbg.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=android_cl...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-02-13 06:14:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/whunt@chromium.org/12207146/7004

[nduca, 2013-02-13 06:38:16]

seriously lgtm

[commit-bot: I haz the power, 2013-02-13 06:39:46]

Retried try job too often on linux_chromeos for step(s) aura_unittests,
browser_tests, content_browsertests, ppapi_unittests, unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...

[jamesr, 2013-02-13 06:43:29]

Super cool!  But how does this make the operations O(1)?  I thought std::set<>
could only promise O(log(n)) for most operations

[whunt, 2013-02-13 20:06:18]

On 2013/02/13 06:43:29, jamesr wrote:
> Super cool!  But how does this make the operations O(1)?  I thought std::set<>
> could only promise O(log(n)) for most operations

you are correct O(log(n)), std::set it a tree not a hash set.

[nduca, 2013-02-13 20:33:46]

Committed manually as r182297.