add new copyTo version to SkBitmap, which takes SkColorType

gm/copyTo4444.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkImageDecoder.h"
@@ skipping 22 matching lines @@
         SkString filename = SkOSPath::SkPathJoin(
                 INHERITED::gResourcePath.c_str(), "mandrill_512.png");
         if (!SkImageDecoder::DecodeFile(filename.c_str(), &bm,
                                         SkBitmap::kARGB_8888_Config,
                                         SkImageDecoder::kDecodePixels_Mode)) {
             SkDebugf("Could not decode the file. Did you forget to set the "
                      "resourcePath?\n");
             return;
         }
         canvas->drawBitmap(bm, 0, 0);
-        SkAssertResult(bm.copyTo(&bm4444, SkBitmap::kARGB_4444_Config));
+        SkAssertResult(bm.copyTo(&bm4444, kARGB_4444_SkColorType));
         canvas->drawBitmap(bm4444, SkIntToScalar(bm.width()), 0);
     }
 
 private:
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new CopyTo4444GM; }
 static GMRegistry reg(MyFactory);
 
 }