Revert of Use flat_set in SurfaceAggregator.

Revert of Use flat_set in SurfaceAggregator. (patchset #3 id:40001 of https://codereview.chromium.org/2821353002/ )

Reason for revert:
Broke cc_unittests SurfaceAggregatorWithResourcesTest.SecureOutputTexture.

https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%281%29/builds/59212

https://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%281%29/builds/62502

Original issue's description:
> Use flat_set in SurfaceAggregator.
> 
> The sets and maps are typically small or empty and created once. flat_set and
> flat_map will have better performance for these workloads.
> 
> See the bug for histograms of sizes.
> 
> Reland of https://codereview.chromium.org/2823043002 with fix.
> 
> BUG=712295
> CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
> TBR=jbauman@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2821353002
> Cr-Commit-Position: refs/heads/master@{#465324}
> Committed: https://chromium.googlesource.com/chromium/src/+/1ac5a973f47b2052df313bab17da120fae22190e

TBR=jbauman@chromium.org,danakj@chromium.org,brettw@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=712295
Review-Url: https://codereview.chromium.org/2826823002
Cr-Commit-Position: refs/heads/master@{#465413}
Committed: https://chromium.googlesource.com/chromium/src/+/1166f4428a18a1cacdeb9e4c310ee7b96cda63b6

[ojan, 2017-04-18 23:01:50]

The CQ bit was checked by ojan@chromium.org

[ojan, 2017-04-18 23:01:51]

Created Revert of Use flat_set in SurfaceAggregator.

[danakj, 2017-04-18 23:02:44]

It's a really awful bug if things are going thru the CQ and breaking unittests
on landing.

[commit-bot: I haz the power, 2017-04-18 23:02:50]

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, 2017-04-18 23:03:54]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492556510705660, "parent_rev":
"87e05d141b5b873725e95585e92f07a6b7ac1fb2", "commit_rev":
"1166f4428a18a1cacdeb9e4c310ee7b96cda63b6"}

[commit-bot: I haz the power, 2017-04-18 23:04:07]

Description was changed from

==========
Revert of Use flat_set in SurfaceAggregator. (patchset #3 id:40001 of
https://codereview.chromium.org/2821353002/ )

Reason for revert:
Broke cc_unittests SurfaceAggregatorWithResourcesTest.SecureOutputTexture.

https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%2...

https://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%2...

Original issue's description:
> Use flat_set in SurfaceAggregator.
> 
> The sets and maps are typically small or empty and created once. flat_set and
> flat_map will have better performance for these workloads.
> 
> See the bug for histograms of sizes.
> 
> Reland of https://codereview.chromium.org/2823043002 with fix.
> 
> BUG=712295
> CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
> TBR=jbauman@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2821353002
> Cr-Commit-Position: refs/heads/master@{#465324}
> Committed:
https://chromium.googlesource.com/chromium/src/+/1ac5a973f47b2052df313bab17da...

TBR=jbauman@chromium.org,danakj@chromium.org,brettw@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=712295
==========

to

==========
Revert of Use flat_set in SurfaceAggregator. (patchset #3 id:40001 of
https://codereview.chromium.org/2821353002/ )

Reason for revert:
Broke cc_unittests SurfaceAggregatorWithResourcesTest.SecureOutputTexture.

https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%2...

https://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%2...

Original issue's description:
> Use flat_set in SurfaceAggregator.
> 
> The sets and maps are typically small or empty and created once. flat_set and
> flat_map will have better performance for these workloads.
> 
> See the bug for histograms of sizes.
> 
> Reland of https://codereview.chromium.org/2823043002 with fix.
> 
> BUG=712295
> CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
> TBR=jbauman@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2821353002
> Cr-Commit-Position: refs/heads/master@{#465324}
> Committed:
https://chromium.googlesource.com/chromium/src/+/1ac5a973f47b2052df313bab17da...

TBR=jbauman@chromium.org,danakj@chromium.org,brettw@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=712295

Review-Url: https://codereview.chromium.org/2826823002
Cr-Commit-Position: refs/heads/master@{#465413}
Committed:
https://chromium.googlesource.com/chromium/src/+/1166f4428a18a1cacdeb9e4c310e...
==========

[commit-bot: I haz the power, 2017-04-18 23:04:11]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/1166f4428a18a1cacdeb9e4c310e...