Dont try to draw glyphs with unexpected mask formats

src/gpu/GrFontScaler.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrFontScaler_DEFINED
 #define GrFontScaler_DEFINED
 
@@ skipping 34 matching lines @@
  */
 class GrFontScaler : public SkRefCnt {
 public:
     explicit GrFontScaler(SkGlyphCache* strike);
     virtual ~GrFontScaler();
     
     const GrFontDescKey* getKey();
     GrMaskFormat getMaskFormat() const;
     GrMaskFormat getPackedGlyphMaskFormat(const SkGlyph&) const;
     bool getPackedGlyphBounds(const SkGlyph&, SkIRect* bounds);
-    bool getPackedGlyphImage(const SkGlyph&, int width, int height, int rowBytes, void* image);
+    bool getPackedGlyphImage(const SkGlyph&, int width, int height, int rowBytes,
+                             GrMaskFormat expectedMaskFormat, void* image);
     bool getPackedGlyphDFBounds(const SkGlyph&, SkIRect* bounds);
     bool getPackedGlyphDFImage(const SkGlyph&, int width, int height, void* image);
     const SkPath* getGlyphPath(const SkGlyph&);
     const SkGlyph& grToSkGlyph(GrGlyph::PackedID);
     
 private:
     SkGlyphCache*  fStrike;
     GrFontDescKey* fKey;
     
     typedef SkRefCnt INHERITED;
 };
 
 #endif