Move distance field generation to the glyph cache

include/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 11 matching lines @@
  */
 class GrFontScaler : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(GrFontScaler)
 
     virtual const GrKey* getKey() = 0;
     virtual GrMaskFormat getMaskFormat() = 0;
     virtual bool getPackedGlyphBounds(GrGlyph::PackedID, SkIRect* bounds) = 0;
     virtual bool getPackedGlyphImage(GrGlyph::PackedID, int width, int height,
                                      int rowBytes, void* image) = 0;
+    // get bounds for distance field associated with packed ID
+    virtual bool getPackedGlyphDFBounds(GrGlyph::PackedID, SkIRect* bounds) = 0;
+    // copies distance field bytes into pre-allocated dfImage
+    // (should be width*height bytes in size)
+    virtual bool getPackedGlyphDFImage(GrGlyph::PackedID, int width, int height,
+                                       void* dfImage) = 0;
     virtual bool getGlyphPath(uint16_t glyphID, SkPath*) = 0;
 
 private:
     typedef SkRefCnt INHERITED;
 };
 
 #endif