change SkDraw and all Blitters to use pixmap instead of bitmap

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 51 matching lines @@
               bool antiAlias, uint8_t alpha);
 
     // Move the mask generation results from the internal bitmap to the gpu.
     void toTexture(GrTexture* texture);
 
     // Convert mask generation results to a signed distance field
     void toSDF(unsigned char* sdf);
     
     // Reset the internal bitmap
     void clear(uint8_t alpha) {
-        fBM.eraseColor(SkColorSetARGB(alpha, alpha, alpha, alpha));
+        fPixels.erase(SkColorSetARGB(alpha, 0xFF, 0xFF, 0xFF));
     }
 
     // Canonical usage utility that draws a single path and uploads it
     // to the GPU. The result is returned.
     static GrTexture* DrawPathMaskToTexture(GrContext* context,
                                             const SkPath& path,
                                             const SkStrokeRec& stroke,
                                             const SkIRect& resultBounds,
                                             bool antiAlias,
                                             const SkMatrix* matrix);
@@ skipping 15 matching lines @@
                                          const SkMatrix& viewMatrix,
                                          const SkIRect& rect);
 
 private:
     // Helper function to get a scratch texture suitable for capturing the
     // result (i.e., right size & format)
     GrTexture* createTexture();
 
     GrContext*      fContext;
     SkMatrix        fMatrix;
-    SkBitmap        fBM;
+    SkAutoPixmapStorage fPixels;
     SkDraw          fDraw;
     SkRasterClip    fRasterClip;
 
     // This enum says whether or not we should compress the mask:
     // kNone_CompressionMode: compression is not supported on this device.
     // kCompress_CompressionMode: compress the bitmap before it gets sent to the gpu
     // kBlitter_CompressionMode: write to the bitmap using a special compressed blitter.
     enum CompressionMode {
         kNone_CompressionMode,
         kCompress_CompressionMode,
@@ skipping 14 matching lines @@
                          const void *data, size_t rowbytes);
 
     // Compresses the bitmap stored in fBM and sends the compressed data
     // to the GPU to be stored in 'texture' using sendTextureData.
     void compressTextureData(GrTexture *texture, const GrSurfaceDesc& desc);
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif // GrSWMaskHelper_DEFINED