speed up A8

src/gpu/GrSWMaskHelper.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrSWMaskHelper_DEFINED
 #define GrSWMaskHelper_DEFINED
 
@@ skipping 30 matching lines @@
 class GrSWMaskHelper : public SkNoncopyable {
 public:
     GrSWMaskHelper(GrContext* context)
     : fContext(context) {
     }
 
     // set up the internal state in preparation for draws. Since many masks
     // may be accumulated in the helper during creation, "resultBounds"
     // allows the caller to specify the region of interest - to limit the
     // amount of work.
-    bool init(const SkIRect& resultBounds, const SkMatrix* matrix);
+    bool init(const SkIRect& resultBounds, const SkMatrix* matrix,
+              bool zeroPixels = true);
 
     // Draw a single rect into the accumulation bitmap using the specified op
     void draw(const SkRect& rect, SkRegion::Op op,
               bool antiAlias, uint8_t alpha);
 
     // Draw a single path into the accumuation bitmap using the specified op
     void draw(const SkPath& path, const SkStrokeRec& stroke, SkRegion::Op op,
               bool antiAlias, uint8_t alpha);
 
     // Helper function to get a scratch texture suitable for capturing the
@@ skipping 36 matching lines @@
     GrContext*      fContext;
     SkMatrix        fMatrix;
     SkBitmap        fBM;
     SkDraw          fDraw;
     SkRasterClip    fRasterClip;
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif // GrSWMaskHelper_DEFINED