Adding an option to render only the shadow in SkDropShadowImageFilter

gm/imagefiltersbase.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 "SkColorFilter.h"
@@ skipping 213 matching lines @@
         };
 
         SkColorFilter* cf = SkColorFilter::CreateModeFilter(SK_ColorRED,
                                                      SkXfermode::kSrcIn_Mode);
         SkImageFilter* filters[] = {
             NULL,
             IdentityImageFilter::Create(),
             FailImageFilter::Create(),
             SkColorFilterImageFilter::Create(cf),
             SkBlurImageFilter::Create(12.0f, 0.0f),
-            SkDropShadowImageFilter::Create(10.0f, 5.0f, 3.0f, 3.0f, SK_ColorBLUE),
+            SkDropShadowImageFilter::Create(10.0f, 5.0f, 3.0f, 3.0f, SK_ColorBLUE,
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
         };
         cf->unref();
 
         SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
         SkScalar MARGIN = SkIntToScalar(16);
         SkScalar DX = r.width() + MARGIN;
         SkScalar DY = r.height() + MARGIN;
 
         canvas->translate(MARGIN, MARGIN);
         for (size_t i = 0; i < SK_ARRAY_COUNT(drawProc); ++i) {
@@ skipping 14 matching lines @@
     }
 
 private:
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static skiagm::GM* MyFactory(void*) { return new ImageFiltersBaseGM; }
 static skiagm::GMRegistry reg(MyFactory);