Revert of Fast blurred rectangles on GPU (https://codereview.chromium.org/119343003/)

Revert of Fast blurred rectangles on GPU (https://codereview.chromium.org/119343003/)

Reason for revert:
Two problems:

1. broke compile on Build-Mac10.6-* bots
2. broke GM expectations on many bots

We'll need to examine the GM impact before re-landing.  I can work with you to do this on Tuesday if you like; just IM or email me.

Original issue's description:
> Perform the same analytic blur calculation on the GPU that we do on the CPU.  Results in significant performance gains when using Ganesh to render drop shadows in Chrome.
>
> BUG=
>
> Committed: http://code.google.com/p/skia/source/detail?r=13210

R=bsalomon@google.com, reed@google.com, humper@google.com, rmistry@google.com
TBR=bsalomon@google.com, humper@google.com, reed@google.com
NOTREECHECKS=true
NOTRY=true
BUG=

Author: epoger@google.com

Review URL: https://codereview.chromium.org/140853008

git-svn-id: http://skia.googlecode.com/svn/trunk@13213 2bbb7eff-a529-9590-31e7-b0007b416f81