Add special case circle blur for Ganesh

src/gpu/GrBlurUtils.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrBlurUtils.h"
 #include "GrDrawContext.h"
 #include "GrCaps.h"
@@ skipping 211 matching lines @@
         // avoid possibly allocating a new path in transform if we can
         SkPath* devPathPtr = pathIsMutable ? pathPtr : tmpPath.init();
         if (!pathIsMutable) {
             devPathPtr->setIsVolatile(true);
         }
 
         // transform the path into device space
         pathPtr->transform(viewMatrix, devPathPtr);
 
         SkRect maskRect;
-        if (paint.getMaskFilter()->canFilterMaskGPU(devPathPtr->getBounds(),
+        if (paint.getMaskFilter()->canFilterMaskGPU(SkRRect::MakeRect(devPathPtr->getBounds()),
                                                     clipBounds,
                                                     viewMatrix,
                                                     &maskRect)) {
             SkIRect finalIRect;
             maskRect.roundOut(&finalIRect);
             if (clip_bounds_quick_reject(clipBounds, finalIRect)) {
                 // clipped out
                 return;
             }
 
@@ skipping 43 matching lines @@
                                                               SkPaint::kFill_Style;
         draw_with_mask_filter(drawContext, context->textureProvider(), renderTarget,
                               clip, viewMatrix, *devPathPtr,
                               paint.getMaskFilter(), clipBounds, &grPaint, style);
         return;
     }
 
     drawContext->drawPath(renderTarget, clip, grPaint, viewMatrix, *pathPtr, strokeInfo);
 }