Split SkPicturePlayback out of SkPictureData

src/utils/SkPictureUtils.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkData.h"
@@ skipping 172 matching lines @@
           if (SkShader::kNone_GradientType == shader->asAGradient(NULL) &&
               shader->asABitmap(&bm, NULL, NULL)) {
               fPRSet->add(bm.pixelRef());
           }
       }
     }
 
     typedef SkBaseDevice INHERITED;
 };
 
-SkData* SkPictureUtils::GatherPixelRefs(SkPicture* pict, const SkRect& area) {
+SkData* SkPictureUtils::GatherPixelRefs(const SkPicture* pict, const SkRect& area) {
     if (NULL == pict) {
         return NULL;
     }
 
     // this test also handles if either area or pict's width/height are empty
     if (!SkRect::Intersects(area,
                             SkRect::MakeWH(SkIntToScalar(pict->width()),
                                            SkIntToScalar(pict->height())))) {
         return NULL;
     }
 
     SkTDArray<SkPixelRef*> array;
     PixelRefSet prset(&array);
 
     GatherPixelRefDevice device(pict->width(), pict->height(), &prset);
     SkNoSaveLayerCanvas canvas(&device);
 
     canvas.clipRect(area, SkRegion::kIntersect_Op, false);
     canvas.drawPicture(pict);
 
     SkData* data = NULL;
     int count = array.count();
     if (count > 0) {
         data = SkData::NewFromMalloc(array.detach(), count * sizeof(SkPixelRef*));
     }
     return data;
 }