Revert of Fix mixed samples stencil clip

Revert of Fix mixed samples stencil clip (patchset #5 id:80001 of https://codereview.chromium.org/1431593006/ )

Reason for revert:
Co-centered sample locations are not needed to do stencil clip with mixed samples.

Original issue's description:
> Fix mixed samples stencil clip
> 
> Fixes rendering bugs and nondeterminism in gm.
> 
> Before, mixed samples stencil clip would try to infer whether the draw
> wanted co-centered sample locations from within GrGLGpu, which caused
> various errors. This change reworks it so the draw itself can request
> the co-centered sample locations when it knows it will need them.
> 
> Also reduces framebuffer binds by moving the code that enables
> GL_FRAMEBUFFER_PROGRAMMABLE_SAMPLE_LOCATIONS into flushRenderTarget.
> 
> Committed: https://skia.googlesource.com/skia/+/14184d5567b58085b6d8a6375796d405056f7f73

TBR=bsalomon@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/d472792a72c0c433a205d42a73e0b77d65f8d76f

[Chris Dalton, 2015-11-10 17:58:41]

Created Revert of Fix mixed samples stencil clip

[commit-bot: I haz the power, 2015-11-10 17:58:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 17:58:51]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-11-10 23:58 UTC

[commit-bot: I haz the power, 2015-11-10 18:01:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 18:31:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 19:01:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 19:31:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 20:00:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 20:30:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[rmistry, 2015-11-10 20:48:35]

The CQ bit was unchecked by rmistry@google.com

[rmistry, 2015-11-10 20:48:39]

rmistry@google.com changed reviewers:
+ rmistry@google.com

[rmistry, 2015-11-10 20:48:40]

lgtm

[rmistry, 2015-11-10 20:48:44]

The CQ bit was checked by rmistry@google.com

[commit-bot: I haz the power, 2015-11-10 20:48:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407063011/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407063011/1

[commit-bot: I haz the power, 2015-11-10 20:49:10]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/d472792a72c0c433a205d42a73e0b77d65f8d76f