Implement an SkPicture image filter source. This is required for the external-SVG reference feature…

gyp/effects.gypi

 # 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.
 #
 {
   'sources': [
     '<(skia_src_path)/effects/Sk1DPathEffect.cpp',
@@ skipping 30 matching lines @@
     '<(skia_src_path)/effects/SkLerpXfermode.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',
     '<(skia_src_path)/effects/SkOffsetImageFilter.cpp',
     '<(skia_src_path)/effects/SkPaintFlagsDrawFilter.cpp',
     '<(skia_src_path)/effects/SkPerlinNoiseShader.cpp',
+    '<(skia_src_path)/effects/SkPictureSource.cpp',
     '<(skia_src_path)/effects/SkPixelXorXfermode.cpp',
     '<(skia_src_path)/effects/SkPorterDuff.cpp',
     '<(skia_src_path)/effects/SkRectShaderImageFilter.cpp',
     '<(skia_src_path)/effects/SkStippleMaskFilter.cpp',
     '<(skia_src_path)/effects/SkTableColorFilter.cpp',
     '<(skia_src_path)/effects/SkTableMaskFilter.cpp',
     '<(skia_src_path)/effects/SkTestImageFilters.cpp',
     '<(skia_src_path)/effects/SkTileImageFilter.cpp',
     '<(skia_src_path)/effects/SkTransparentShader.cpp',
     '<(skia_src_path)/effects/SkXfermodeImageFilter.cpp',
@@ skipping 51 matching lines @@
     '<(skia_include_path)/effects/SkPorterDuff.h',
     '<(skia_include_path)/effects/SkRectShaderImageFilter.h',
     '<(skia_include_path)/effects/SkStippleMaskFilter.h',
     '<(skia_include_path)/effects/SkTableColorFilter.h',
     '<(skia_include_path)/effects/SkTableMaskFilter.h',
     '<(skia_include_path)/effects/SkTileImageFilter.h',
     '<(skia_include_path)/effects/SkTransparentShader.h',
     '<(skia_include_path)/effects/SkMagnifierImageFilter.h',
   ],
 }