add SkPixmap and external locking to bitmaps

include/core/SkBitmap.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBitmap_DEFINED
 #define SkBitmap_DEFINED
 
 #include "SkColor.h"
 #include "SkColorTable.h"
 #include "SkImageInfo.h"
+#include "SkPixmap.h"
 #include "SkPoint.h"
 #include "SkRefCnt.h"
 
 struct SkMask;
 struct SkIRect;
 struct SkRect;
 class SkPaint;
 class SkPixelRef;
 class SkPixelRefFactory;
 class SkRegion;
@@ skipping 397 matching lines @@
     void unlockPixels() const;
 
     /**
      *  Some bitmaps can return a copy of their pixels for lockPixels(), but
      *  that copy, if modified, will not be pushed back. These bitmaps should
      *  not be used as targets for a raster device/canvas (since all pixels
      *  modifications will be lost when unlockPixels() is called.)
      */
     bool lockPixelsAreWritable() const;
 
+    bool requestLock(SkAutoPixmapUnlock* result) const;
+
     /** Call this to be sure that the bitmap is valid enough to be drawn (i.e.
         it has non-null pixels, and if required by its colortype, it has a
         non-null colortable. Returns true if all of the above are met.
     */
     bool readyToDraw() const {
         return this->getPixels() != NULL &&
                (this->colorType() != kIndex_8_SkColorType || fColorTable);
     }
 
     /** Returns the pixelRef's texture, or NULL
@@ skipping 345 matching lines @@
 
 inline SkPMColor SkBitmap::getIndex8Color(int x, int y) const {
     SkASSERT(fPixels);
     SkASSERT(kIndex_8_SkColorType == this->colorType());
     SkASSERT((unsigned)x < (unsigned)this->width() && (unsigned)y < (unsigned)this->height());
     SkASSERT(fColorTable);
     return (*fColorTable)[*((const uint8_t*)fPixels + y * fRowBytes + x)];
 }
 
 #endif