Add query for block dimensions of a given format

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
 
 #include "GrColor.h"
 #include "GrDrawState.h"
 #include "SkBitmap.h"
 #include "SkDraw.h"
 #include "SkMatrix.h"
 #include "SkRasterClip.h"
 #include "SkRegion.h"
+#include "SkTextureCompressor.h"
 #include "SkTypes.h"
 
 class GrAutoScratchTexture;
 class GrContext;
 class GrTexture;
 class SkPath;
 class SkStrokeRec;
 class GrDrawTarget;
 
 /**
@@ skipping 66 matching lines @@
                                          const SkIRect& rect);
 
 protected:
 private:
     GrContext*      fContext;
     SkMatrix        fMatrix;
     SkBitmap        fBM;
     SkDraw          fDraw;
     SkRasterClip    fRasterClip;
 
+#if GR_COMPRESS_ALPHA_MASK
+    SkTextureCompressor::Format fCompressedFormat;
+#endif
+
     // Actually sends the texture data to the GPU. This is called from
     // toTexture with the data filled in depending on the texture config.
     void sendTextureData(GrTexture *texture, const GrTextureDesc& desc,
                          const void *data, int 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 GrTextureDesc& desc);
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif // GrSWMaskHelper_DEFINED