Add alternative ambient shadow method to Android shadow sample

gyp/effects.gypi

 # 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 this gypi to include all 'effects' files
 # The parent gyp/gypi file must define:
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi.
@@ skipping 26 matching lines @@
     '<(skia_src_path)/effects/SkDashPathEffect.cpp',
     '<(skia_src_path)/effects/SkDiscretePathEffect.cpp',
     '<(skia_src_path)/effects/SkDisplacementMapEffect.cpp',
     '<(skia_src_path)/effects/SkDropShadowImageFilter.cpp',
     '<(skia_src_path)/effects/SkEmbossMask.cpp',
     '<(skia_src_path)/effects/SkEmbossMask.h',
     '<(skia_src_path)/effects/SkEmbossMask_Table.h',
     '<(skia_src_path)/effects/SkEmbossMaskFilter.cpp',
     '<(skia_src_path)/effects/SkImageSource.cpp',
     '<(skia_src_path)/effects/SkGammaColorFilter.cpp',
+    '<(skia_src_path)/effects/SkGaussianEdgeShader.cpp',
     '<(skia_src_path)/effects/SkGpuBlurUtils.h',
     '<(skia_src_path)/effects/SkGpuBlurUtils.cpp',
     '<(skia_src_path)/effects/SkLayerDrawLooper.cpp',
     '<(skia_src_path)/effects/SkLayerRasterizer.cpp',
     '<(skia_src_path)/effects/SkLightingImageFilter.cpp',
     '<(skia_src_path)/effects/SkLumaColorFilter.cpp',
     '<(skia_src_path)/effects/SkMagnifierImageFilter.cpp',
     '<(skia_src_path)/effects/SkMatrixConvolutionImageFilter.cpp',
     '<(skia_src_path)/effects/SkMergeImageFilter.cpp',
     '<(skia_src_path)/effects/SkMorphologyImageFilter.cpp',
@@ skipping 42 matching lines @@
     '<(skia_include_path)/effects/SkColorFilterImageFilter.h',
     '<(skia_include_path)/effects/SkColorMatrix.h',
     '<(skia_include_path)/effects/SkColorMatrixFilter.h',
     '<(skia_include_path)/effects/SkCornerPathEffect.h',
     '<(skia_include_path)/effects/SkDashPathEffect.h',
     '<(skia_include_path)/effects/SkDiscretePathEffect.h',
     '<(skia_include_path)/effects/SkDisplacementMapEffect.h',
     '<(skia_include_path)/effects/SkDropShadowImageFilter.h',
     '<(skia_include_path)/effects/SkEmbossMaskFilter.h',
     '<(skia_include_path)/effects/SkGammaColorFilter.h',
+    '<(skia_include_path)/effects/SkGaussianEdgeShader.h',
     '<(skia_include_path)/effects/SkGradientShader.h',
     '<(skia_include_path)/effects/SkImageSource.h',
     '<(skia_include_path)/effects/SkLayerDrawLooper.h',
     '<(skia_include_path)/effects/SkLayerRasterizer.h',
     '<(skia_include_path)/effects/SkLightingImageFilter.h',
     '<(skia_include_path)/effects/SkLumaColorFilter.h',
     '<(skia_include_path)/effects/SkMagnifierImageFilter.h',
     '<(skia_include_path)/effects/SkMorphologyImageFilter.h',
     '<(skia_include_path)/effects/SkOffsetImageFilter.h',
     '<(skia_include_path)/effects/SkPaintFlagsDrawFilter.h',
     '<(skia_include_path)/effects/SkPaintImageFilter.h',
     '<(skia_include_path)/effects/SkPerlinNoiseShader.h',
     '<(skia_include_path)/effects/SkTableColorFilter.h',
     '<(skia_include_path)/effects/SkTableMaskFilter.h',
     '<(skia_include_path)/effects/SkTileImageFilter.h',
     '<(skia_include_path)/effects/SkXfermodeImageFilter.h',
   ],
 }