More changes to SkPDFShader to eliminate multiple inheritance!

src/pdf/SkPDFCanon.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkPDFCanon_DEFINED
 #define SkPDFCanon_DEFINED
 
 #include "SkPDFShader.h"
 #include "SkThread.h"
 #include "SkTDArray.h"
 
 struct SkIRect;
 class SkMatrix;
 class SkPDFFont;
 class SkPDFGraphicState;
 class SkPaint;
-class SkShader;
 
 // This class's fields and methods will eventually become part of
 // SkPDFDocument/SkDocument_PDF.  For now, it exists as a singleton to
 // preflight that transition.  This replaces three global arrays in
 // SkPDFFont, SkPDFShader, and SkPDFGraphicsContext.
 //
 // IF YOU ARE LOOKING AT THIS API PLEASE DO NOT WRITE THE CHANGE
 // YOU ARE ABOUT TO WRITE WITHOUT TALKING TO HALCANARY@.
 //
 // Note that this class does not create, delete, reference or
@@ skipping 14 matching lines @@
 
     // Returns exact match if there is one.  If not, it returns NULL.
     // If there is no exact match, but there is a related font, we
     // still return NULL, but also set *relatedFont.
     SkPDFFont* findFont(uint32_t fontID,
                         uint16_t glyphID,
                         SkPDFFont** relatedFont) const;
     void addFont(SkPDFFont* font, uint32_t fontID, uint16_t fGlyphID);
     void removeFont(SkPDFFont*);
 
-    SkPDFShader* findShader(const SkPDFShader::State&) const;
-    void addShader(SkPDFShader*);
-    void removeShader(SkPDFShader*);
+    SkPDFFunctionShader* findFunctionShader(const SkPDFShader::State&) const;
+    void addFunctionShader(SkPDFFunctionShader*);
+    void removeFunctionShader(SkPDFFunctionShader*);
+
+    SkPDFAlphaFunctionShader* findAlphaShader(const SkPDFShader::State&) const;
+    void addAlphaShader(SkPDFAlphaFunctionShader*);
+    void removeAlphaShader(SkPDFAlphaFunctionShader*);
+
+    SkPDFImageShader* findImageShader(const SkPDFShader::State&) const;
+    void addImageShader(SkPDFImageShader*);
+    void removeImageShader(SkPDFImageShader*);
 
     SkPDFGraphicState* findGraphicState(const SkPaint&) const;
     void addGraphicState(SkPDFGraphicState*);
     void removeGraphicState(SkPDFGraphicState*);
 
 private:
     struct FontRec {
         SkPDFFont* fFont;
         uint32_t fFontID;
         uint16_t fGlyphID;
     };
     SkTDArray<FontRec> fFontRecords;
 
-    SkTDArray<SkPDFShader*> fShaderRecords;
+    SkTDArray<SkPDFFunctionShader*> fFunctionShaderRecords;
+
+    SkTDArray<SkPDFAlphaFunctionShader*> fAlphaShaderRecords;
+
+    SkTDArray<SkPDFImageShader*> fImageShaderRecords;
 
     SkTDArray<SkPDFGraphicState*> fGraphicStateRecords;
 };
 #endif  // SkPDFCanon_DEFINED