Revert of Fix assorted issues with remote CoreAnimation

Revert of Fix assorted issues with remote CoreAnimation (patchset #2 of https://codereview.chromium.org/516643002/)

Reason for revert:
Speculatively reverting to see if this helps the mac perf bots:
https://code.google.com/p/chromium/issues/detail?id=408673

Original issue's description:
> Fix assorted issues with remote CoreAnimation
> 
> These issues came up while running for a few days with the
> flag --enable-remote-core-animation.
> 
> Fix flashes of old frames by hooking up the DiscardBackbuffer (which
> happens when being made non-visible) to re-set the CAContext and
> CALayer (so the browser gets a new one with new content for the next
> frame).
> 
> Add support for disabling vsync by using setNeedsDisplay to draw.
> 
> Change the backpressure mechanism to rely on the browser to apply
> backpressure in its compositor via the cc:: output surface.
> 
> Add a ScopedSetGLToRealGLApi structure to ensure that we are talking
> to the real GL API while in the CoreAnimation callback.
> 
> BUG=312462
> 
> Committed: https://chromium.googlesource.com/chromium/src/+/3b6aee8ed0393d852ed21fae78f539ffffe3e8f8

TBR=piman@chromium.org,ccameron@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=312462
Committed: https://crrev.com/f7fd083dbff47a60bd6da12006db1db7b1b4cb43
Cr-Commit-Position: refs/heads/master@{#292438}

[epenner, 2014-08-28 18:22:33]

Created Revert of Fix assorted issues with remote CoreAnimation

[commit-bot: I haz the power, 2014-08-28 18:23:48]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/epenner@chromium.org/517733002/1

[commit-bot: I haz the power, 2014-08-28 19:13:20]

Committed patchset #1 (id:1) as 07539c445c9fa7161b3da9031cf440a2b657dd18

[ccameron, 2014-08-28 22:33:28]

A revert of this CL (patchset #1) has been created in
https://codereview.chromium.org/517143002/ by ccameron@chromium.org.

The reason for reverting is: Patch was reverted in error.

[commit-bot: I haz the power, 2014-09-10 03:01:23]

Patchset 1 (id:??) landed as
https://crrev.com/f7fd083dbff47a60bd6da12006db1db7b1b4cb43
Cr-Commit-Position: refs/heads/master@{#292438}