Revert of Enable BeginFrame scheduling on aura

Revert of Enable BeginFrame scheduling on aura (patchset #15 id:270001 of https://codereview.chromium.org/1016033006/)

Reason for revert:
Making Autofill interactive tests incredibly flaky again:
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20(1)
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Ozone%20Tests%20%281%29/

Original issue's description:
> Enable BeginFrame scheduling on aura
>
> This cl is last partial cl from https://codereview.chromium.org/775143003/
> for easy review.
> Until now, BeginFrame is initiated by each renderer process.
> With this cl, BeginFrame is scheduled from parent(browser) cc scheduler
> to child(renderer) cc scheduler.
> For more detailed information, please see this (http://goo.gl/D1Qxrr)
>
> Also, --enable-begin-frame-scheduling is no longer needed because all platform except Mac
> uses it as a default.
>
> R=brianderson@chromium.org, danakj@chromium.org, mithro@mithis.com
> BUG=372086
>
> Committed: https://crrev.com/17dd2f109f3155ebf183627b63df25f97f34b67f
> Cr-Commit-Position: refs/heads/master@{#322622}
>
> Committed: https://crrev.com/62a759e582743bca13f27d1ce5db3dc2fe66fbb6
> Cr-Commit-Position: refs/heads/master@{#328170}

TBR=brianderson@chromium.org,danakj@chromium.org,mithro@mithis.com,sievers@chromium.org,oshima@chromium.org,boliu@chromium.org,simonhong@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=372086
Committed: https://crrev.com/e627c5239eed0c99cbb7c9973d9241c125aaaed3
Cr-Commit-Position: refs/heads/master@{#328267}

[Dan Beam, 2015-05-05 03:24:11]

Created Revert of Enable BeginFrame scheduling on aura

[commit-bot: I haz the power, 2015-05-05 03:24:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1124523003/1

[commit-bot: I haz the power, 2015-05-05 03:26:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-05 03:26:57]

Patchset 1 (id:??) landed as
https://crrev.com/e627c5239eed0c99cbb7c9973d9241c125aaaed3
Cr-Commit-Position: refs/heads/master@{#328267}