add new copyTo version to SkBitmap, which takes SkColorType

src/image/SkImage_Raster.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 "SkImage_Base.h"
 #include "SkImagePriv.h"
 #include "SkBitmap.h"
@@ skipping 109 matching lines @@
 }
 
 bool SkImage_Raster::onReadPixels(SkBitmap* dst, const SkIRect& subset) const {
     if (dst->pixelRef()) {
         return this->INHERITED::onReadPixels(dst, subset);
     } else {
         SkBitmap src;
         if (!fBitmap.extractSubset(&src, subset)) {
             return false;
         }
-        return src.copyTo(dst, src.config());
+        return src.copyTo(dst, src.colorType());
     }
 }
 
 const void* SkImage_Raster::onPeekPixels(SkImageInfo* infoPtr,
                                          size_t* rowBytesPtr) const {
     SkImageInfo info;
     if (!fBitmap.asImageInfo(&info) || !fBitmap.getPixels()) {
         return NULL;
     }
     *infoPtr = info;
@@ skipping 48 matching lines @@
 }
 
 SkImage* SkNewImageFromPixelRef(const SkImageInfo& info, SkPixelRef* pr,
                                 size_t rowBytes) {
     return SkNEW_ARGS(SkImage_Raster, (info, pr, rowBytes));
 }
 
 SkPixelRef* SkBitmapImageGetPixelRef(SkImage* image) {
     return ((SkImage_Raster*)image)->getPixelRef();
 }