remove unused GM flags

gm/peekpixels.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 "gm.h"
 #include "SkCanvas.h"
 #include "SkPath.h"
@@ skipping 46 matching lines @@
             if (ropixels.asROBitmap(&bitmap)) {
                 canvas->drawBitmap(bitmap, 0, 0, NULL);
             }
 
             // test Surface
             canvas->translate(120, 0);
             surface->draw(canvas, 0, 0, NULL);
         }
     }
 
-    uint32_t onGetFlags() const SK_OVERRIDE {
-        // we explicitly test peekPixels and readPixels, neither of which
-        // return something for a picture-backed canvas, so we skip that test.
-        return kSkipPicture_Flag;
-    }
-
 private:
     typedef skiagm::GM INHERITED;
 };
 
 DEF_GM( return SkNEW(PeekPixelsGM); )