hide discardable factory from public imagegenerator api

samplecode/SamplePicture.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleCode.h"
 #include "SkData.h"
 #include "SkDecodingImageGenerator.h"
@@ skipping 23 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static SkBitmap load_bitmap() {
     SkBitmap bm;
     SkString directory = skiagm::GM::GetResourcePath();
     SkString path = SkOSPath::SkPathJoin(directory.c_str(), "mandrill_512.png");
     SkAutoDataUnref data(SkData::NewFromFileName(path.c_str()));
     if (data.get() != NULL) {
         SkInstallDiscardablePixelRef(SkDecodingImageGenerator::Create(
-            data, SkDecodingImageGenerator::Options()), &bm, NULL);
+            data, SkDecodingImageGenerator::Options()), &bm);
     }
     return bm;
 }
 
 static void drawCircle(SkCanvas* canvas, int r, SkColor color) {
     SkPaint paint;
     paint.setAntiAlias(true);
     paint.setColor(color);
 
     canvas->drawCircle(SkIntToScalar(r), SkIntToScalar(r), SkIntToScalar(r),
@@ skipping 137 matching lines @@
     SkPicture*  fPicture;
     SkPicture*  fSubPicture;
 
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new PictureView; }
 static SkViewRegister reg(MyFactory);