Implement GPU occluded blur mask filter

src/core/SkMaskFilter.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkMaskFilter.h"
 #include "SkBlitter.h"
@@ skipping 312 matching lines @@
     return false;
 }
 
 
 bool SkMaskFilter::directFilterRRectMaskGPU(GrContext*,
                                             GrDrawContext* drawContext,
                                             GrPaint* grp,
                                             const GrClip&,
                                             const SkMatrix& viewMatrix,
                                             const SkStrokeRec& strokeRec,
-                                            const SkRRect& rrect) const {
+                                            const SkRRect& rrect,
+                                            const SkRRect& devRRect) const {
     return false;
 }
 
 bool SkMaskFilter::filterMaskGPU(GrTexture* src,
                                  const SkMatrix& ctm,
                                  const SkIRect& maskRect,
                                  GrTexture** result) const {
     return false;
 }
 #endif
 
 void SkMaskFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
     SkMask  srcM, dstM;
 
     srcM.fBounds = src.roundOut();
     srcM.fRowBytes = 0;
     srcM.fFormat = SkMask::kA8_Format;
 
     SkIPoint margin;    // ignored
     if (this->filterMask(&dstM, srcM, SkMatrix::I(), &margin)) {
         dst->set(dstM.fBounds);
     } else {
         dst->set(srcM.fBounds);
     }
 }