Revert of android: Migrate old content readback to use async readback (and delegated renderer)

Revert of android: Migrate old content readback to use async readback (and delegated renderer) (https://codereview.chromium.org/143803004/)

Reason for revert:
broke android build

Original issue's description:
> android: Migrate old content readback to use async readback (and delegated renderer)
> 
> This patch removes the use of a helper context for content readback.  Instead,
> we use the async readback API.
> 
> This patch is also setting delegated renderer as the default for android.
> 
> android= https://chrome-internal-review.googlesource.com/#/c/153667/
> 
> BUG=326363
> TBR=sievers
> NOTRY=true
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=248827
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=249081

TBR=dtrainor@chromium.org,aelias@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=326363
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=249175

[powei, 2014-02-06 00:04:11]

Created Revert of android: Migrate old content readback to use async readback
(and delegated renderer)

[commit-bot: I haz the power, 2014-02-06 00:08:58]

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

[commit-bot: I haz the power, 2014-02-06 00:08:58]

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 lowly 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.

[Yusuf, 2014-02-06 00:11:55]

lgtm

[powei, 2014-02-06 00:13:02]

The CQ bit was checked by powei@chromium.org

[commit-bot: I haz the power, 2014-02-06 00:15:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/powei@chromium.org/151103010/1

[commit-bot: I haz the power, 2014-02-06 00:22:06]

Change committed as 249175