discardable pixelrefs are gone, update tests accordingly

gm/pictureimagegenerator.cpp

 /*
  * Copyright 2015 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 "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 142 matching lines @@
             if (configs[i].scaleX < 0) {
                 m.postTranslate(SkIntToScalar(configs[i].size.width()), 0);
             }
             if (configs[i].scaleY < 0) {
                 m.postTranslate(0, SkIntToScalar(configs[i].size.height()));
             }
             SkAutoTDelete<SkImageGenerator> gen(
                 SkImageGenerator::NewFromPicture(configs[i].size, fPicture.get(), &m,
                                                  p.getAlpha() != 255 ? &p : nullptr));
             SkBitmap bm;
-            SkAssertResult(SkInstallDiscardablePixelRef(gen.detach(), &bm));
+            gen->generateBitmap(&bm);
 
             const SkScalar x = kDrawSize * (i % kDrawsPerRow);
             const SkScalar y = kDrawSize * (i / kDrawsPerRow);
 
             p.setColor(0xfff0f0f0);
             p.setAlpha(255);
             canvas->drawRect(SkRect::MakeXYWH(x, y,
                                               SkIntToScalar(bm.width()),
                                               SkIntToScalar(bm.height())), p);
             canvas->drawBitmap(bm, x, y);
         }
     }
 
 private:
     SkAutoTUnref<SkPicture> fPicture;
 
     const SkScalar kPictureWidth = 200;
     const SkScalar kPictureHeight = 100;
 
     typedef skiagm::GM INHERITED;
 };
 
 DEF_GM(return new PictureGeneratorGM;)