Revert of Simplify IOSurface CoreAnimation code: Part 2

Revert of Simplify IOSurface CoreAnimation code: Part 2 (patchset #13 id:240001 of https://codereview.chromium.org/490393002/)

Reason for revert:
crbug.com/410360	(Browser crashing on IOSurfaceLayer release in tab_switching.typical_25)

Original issue's description:
> Simplify IOSurface CoreAnimation code: Part 2
> 
> It isn't necessary to mess around with sharing CGLContextObjs anymore,
> they were necessary only to share data between the frame subscriber
> and the RenderWidgetHostViewMac. Just give each IOSurfaceLayer its
> own CGLContextObj, and draw using immediate mode (using shaders
> resulted in an increase in startup time).
> 
> BUG=314190
> TBR=pfeldman@chromium.org
> R=kbr@chromium.org
> 
> Committed: https://chromium.googlesource.com/chromium/src/+/a83898264f64ad83bb98139e5e0dcb2c77db1997

TBR=kbr@chromium.org,ccameron@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=314190
Committed: https://crrev.com/9cde44e2ac2ae2933ab67cbfef13bc75dfa16502
Cr-Commit-Position: refs/heads/master@{#293174}

[aiolos (Not reviewing), 2014-09-03 17:12:51]

Created Revert of Simplify IOSurface CoreAnimation code: Part 2

[commit-bot: I haz the power, 2014-09-03 17:14:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/aiolos@chromium.org/528403002/1

[commit-bot: I haz the power, 2014-09-03 17:14:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-03 17:14:02]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[sullivan, 2014-09-03 17:15:40]

sullivan@chromium.org changed reviewers:
+ sullivan@chromium.org

[sullivan, 2014-09-03 17:15:40]

lgtm

[aiolos (Not reviewing), 2014-09-03 17:15:59]

The CQ bit was checked by aiolos@chromium.org

[commit-bot: I haz the power, 2014-09-03 17:17:11]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/aiolos@chromium.org/528403002/1

[commit-bot: I haz the power, 2014-09-03 18:21:41]

Committed patchset #1 (id:1) as ce21597b7aa982e9f06202153fea6750053db7db

[commit-bot: I haz the power, 2014-09-10 03:26:59]

Patchset 1 (id:??) landed as
https://crrev.com/9cde44e2ac2ae2933ab67cbfef13bc75dfa16502
Cr-Commit-Position: refs/heads/master@{#293174}