Implement GPU occluded blur mask filter

src/gpu/SkGpuDevice_drawTexture.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 "SkGpuDevice.h"
 
 #include "GrBlurUtils.h"
@@ skipping 214 matching lines @@
     }
 
     // First see if we can do the draw + mask filter direct to the dst.
     SkStrokeRec rec(SkStrokeRec::kFill_InitStyle);
     if (mf->directFilterRRectMaskGPU(fContext,
                                       fDrawContext.get(),
                                       &grPaint,
                                       clip,
                                       viewMatrix,
                                       rec,
+                                      SkRRect::MakeRect(clippedSrcRect),
                                       SkRRect::MakeRect(clippedDstRect))) {
         return;
     }
     SkPath rectPath;
     rectPath.addRect(clippedDstRect);
     rectPath.setIsVolatile(true);
     GrBlurUtils::drawPathWithMaskFilter(this->context(), fDrawContext.get(), fClip,
                                         rectPath, &grPaint, viewMatrix, mf, GrStyle::SimpleFill(),
                                         true);
 }