Revert of Remove GrStagedProcessor, remove the word Stage as it applies to FPs

Revert of Remove GrStagedProcessor, remove the word Stage as it applies to FPs (patchset #6 id:90001 of https://codereview.chromium.org/1307223004/ )

Reason for revert:
Causes bot failures:

https://uberchromegw.corp.google.com/i/client.skia/builders/Test-Mac10.9-Clang-MacMini6.2-GPU-HD4000-x86_64-Debug/builds/1639

https://uberchromegw.corp.google.com/i/client.skia/builders/Test-Ubuntu-GCC-ShuttleA-GPU-GTX660-x86_64-Debug/builds/1702

https://uberchromegw.corp.google.com/i/client.skia.android/builders/Test-Android-GCC-NexusPlayer-GPU-PowerVR-x86-Debug/builds/1223

Original issue's description:
> Remove GrStagedProcessor, remove the word Stage as it applies to FPs
> 
> Committed: https://skia.googlesource.com/skia/+/24243446cdf7b7e4e132c2a0c387c7723777e0c7

TBR=joshualitt@google.com,egdaniel@google.com,bsalomon@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/4bf69f7bbc073c1dc257f93f8c5b2a530123cb3c

[rmistry, 2015-08-26 13:48:13]

Created Revert of Remove GrStagedProcessor, remove the word Stage as it applies
to FPs

[commit-bot: I haz the power, 2015-08-26 13:48:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1306803003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1306803003/1

[commit-bot: I haz the power, 2015-08-26 13:48:31]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/4bf69f7bbc073c1dc257f93f8c5b2a530123cb3c