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
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 6160876..73eb65b 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -933,7 +933,7 @@
 
         // transform the path into device space
         pathPtr->transform(fContext->getMatrix(), devPathPtr);
-        
+
         SkRect maskRect;
         if (paint.getMaskFilter()->canFilterMaskGPU(devPathPtr->getBounds(),
                                                     draw.fClip->getBounds(),
@@ -953,13 +953,6 @@
                 // nothing to draw
                 return;
             }
-            
-            if (paint.getMaskFilter()->directFilterMaskGPU(fContext, &grPaint,
-                                                           SkStrokeRec(paint), *devPathPtr)) {
-                // the mask filter was able to draw itself directly, so there's nothing
-                // left to do.
-                return;
-            }
 
             GrAutoScratchTexture mask;