add SkImage::NewFromPicture and a GM to test it

include/core/SkImage.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImage_DEFINED
 #define SkImage_DEFINED
 
 #include "SkFilterQuality.h"
 #include "SkImageInfo.h"
 #include "SkImageEncoder.h"
 #include "SkRefCnt.h"
 #include "SkScalar.h"
 #include "SkShader.h"
 
 class SkData;
 class SkCanvas;
 class SkColorTable;
 class SkImageGenerator;
 class SkPaint;
+class SkPicture;
 class SkString;
 class SkSurface;
 class SkSurfaceProps;
 class GrContext;
 class GrTexture;
 
 /**
  *  SkImage is an abstraction for drawing a rectagle of pixels, though the
  *  particular type of image could be actually storing its data on the GPU, or
  *  as drawing commands (picture or PDF or otherwise), ready to be played back
@@ skipping 101 matching lines @@
     /**
      *  Create a new image by copying the pixels from the specified y, u, v textures. The data
      *  from the textures is immediately ingested into the image and the textures can be modified or
      *  deleted after the function returns. The image will have the dimensions of the y texture.
      */
     static SkImage* NewFromYUVTexturesCopy(GrContext*, SkYUVColorSpace,
                                            const GrBackendObject yuvTextureHandles[3],
                                            const SkISize yuvSizes[3],
                                            GrSurfaceOrigin);
 
+    static SkImage* NewFromPicture(const SkPicture*, const SkISize& dimensions,
+                                   const SkMatrix*, const SkPaint*);
+
+    ///////////////////////////////////////////////////////////////////////////////////////////////
+
     int width() const { return fWidth; }
     int height() const { return fHeight; }
     uint32_t uniqueID() const { return fUniqueID; }
     virtual bool isOpaque() const { return false; }
 
     virtual SkShader* newShader(SkShader::TileMode,
                                 SkShader::TileMode,
                                 const SkMatrix* localMatrix = NULL) const;
 
     /**
@@ skipping 133 matching lines @@
 
 private:
     const int       fWidth;
     const int       fHeight;
     const uint32_t  fUniqueID;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif