change internals over to SkPixmap and stop using accessBitmap

include/core/SkPixmap.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 SkPixmap_DEFINED
 #define SkPixmap_DEFINED
 
@@ skipping 15 matching lines @@
              SkColorTable* ctable = NULL)
         : fPixels(addr), fCTable(ctable), fRowBytes(rowBytes), fInfo(info)
     {
         if (kIndex_8_SkColorType == info.colorType()) {
             SkASSERT(ctable);
         } else {
             SkASSERT(NULL == ctable);
         }
     }
 
+    void reset();
+    void reset(const SkImageInfo& info, const void* addr, size_t rowBytes,
+               SkColorTable* ctable = NULL);
+
     const SkImageInfo& info() const { return fInfo; }
     size_t rowBytes() const { return fRowBytes; }
     const void* addr() const { return fPixels; }
     SkColorTable* ctable() const { return fCTable; }
 
     int width() const { return fInfo.width(); }
     int height() const { return fInfo.height(); }
     SkColorType colorType() const { return fInfo.colorType(); }
     SkAlphaType alphaType() const { return fInfo.alphaType(); }
     bool isOpaque() const { return fInfo.isOpaque(); }
@@ skipping 112 matching lines @@
 private:
     void        (*fUnlockProc)(void*);
     void*       fUnlockContext;
     SkPixmap    fPixmap;
     bool        fIsLocked;
 
     friend class SkBitmap;
 };
 
 #endif