Revert of [Temporary On Will revert on Fri] UI impl side painting default on

Revert of [Temporary On Will revert on Fri] UI impl side painting default on (patchset #12 id:290001 of https://codereview.chromium.org/962833003/)

Reason for revert:
I suspect this CL broke the MSan bots, see https://crbug.com/479133
The trybots are happy upon revert.

Original issue's description:
> [Temporary On will revert on Fri]UI impl side painting default on
>
> Turn on Impl Side Painting on Aura browser compositor by default
> and add a disable compositor switch.
>
> Temporarily turn on this patch to flush out potential bugs. Will
> revert on Friday.
>
> R=danakj
> BUG=314185
>
> Committed: https://crrev.com/ee6eff90528b8c5b0c10e6faf643edac074ff4b7
> Cr-Commit-Position: refs/heads/master@{#325985}

TBR=danakj@chromium.org,enne@chromium.org,piman@chromium.org,reveman@chromium.org,weiliangc@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=314185
Committed: https://crrev.com/7859e71922205e241ef91d20a5b9032c90e6d4d3
Cr-Commit-Position: refs/heads/master@{#326276}

[Alexander Potapenko, 2015-04-21 13:59:28]

Created Revert of [Temporary On Will revert on Fri] UI impl side painting
default on

[Alexander Potapenko, 2015-04-22 12:55:44]

The CQ bit was checked by glider@chromium.org

[commit-bot: I haz the power, 2015-04-22 12:56:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092933005/1

[commit-bot: I haz the power, 2015-04-22 12:56:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-22 12:57:38]

Patchset 1 (id:??) landed as
https://crrev.com/7859e71922205e241ef91d20a5b9032c90e6d4d3
Cr-Commit-Position: refs/heads/master@{#326276}