Adding an option to render only the shadow in SkDropShadowImageFilter

gm/imagefilterscropexpand.cpp

 /*
  * Copyright 2014 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 "SkColorFilter.h"
@@ skipping 124 matching lines @@
                 8.0f, 8.0f, noop_cropped.get(), &big_rect));
 
             draw(canvas, checkerboard, rect, SkDilateImageFilter::Create(
                 2, 2, noop_cropped.get(), &big_rect));
 
             draw(canvas, checkerboard, rect, SkErodeImageFilter::Create(
                 2, 2, noop_cropped.get(), &big_rect));
 
             draw(canvas, checkerboard, rect, SkDropShadowImageFilter::Create(
                 SkIntToScalar(10), SkIntToScalar(10), SkIntToScalar(3), SkIntToScalar(3),
-                SK_ColorBLUE, noop_cropped.get(), &big_rect));
+                SK_ColorBLUE, SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode,
+                noop_cropped.get(), &big_rect, 0));
 
             draw(canvas, checkerboard, rect, SkDisplacementMapEffect::Create(
                 SkDisplacementMapEffect::kR_ChannelSelectorType,
                 SkDisplacementMapEffect::kR_ChannelSelectorType,
                 SkIntToScalar(12),
                 gradient_circle_source.get(),
                 noop_cropped.get(),
                 &big_rect));
 
             draw(canvas, checkerboard, rect, SkOffsetImageFilter::Create(
                 SkIntToScalar(-8), SkIntToScalar(16), noop_cropped.get(), &big_rect));
 
             canvas->restore();
             canvas->translate(0, SkIntToScalar(80));
         }
     }
 
 private:
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static skiagm::GM* MyFactory(void*) { return new ImageFiltersCropExpandGM; }
 static skiagm::GMRegistry reg(MyFactory);