add inital gm for colorfilters

gyp/gmslides.gypi

 # include this gypi to include all the golden master slides.
 {
   'include_dirs': [
     '../gm',
     # include dirs needed by particular GMs
     '../src/utils/debugger',
     '../src/images',
     '../src/lazy',
   ],
   'sources': [
@@ skipping 25 matching lines @@
     '../gm/blurs.cpp',
     '../gm/blurquickreject.cpp',
     '../gm/blurrect.cpp',
     '../gm/blurroundrect.cpp',
     '../gm/canvasstate.cpp',
     '../gm/circles.cpp',
     '../gm/circularclips.cpp',
     '../gm/clippedbitmapshaders.cpp',
     '../gm/coloremoji.cpp',
     '../gm/colorfilterimagefilter.cpp',
+    '../gm/colorfilters.cpp',
     '../gm/colormatrix.cpp',
     '../gm/colortype.cpp',
     '../gm/complexclip.cpp',
     '../gm/complexclip2.cpp',
     '../gm/composeshader.cpp',
     #'../gm/conicpaths.cpp',
     '../gm/convexpaths.cpp',
     '../gm/convexpolyclip.cpp',
     '../gm/convexpolyeffect.cpp',
     '../gm/copyTo4444.cpp',
@@ skipping 117 matching lines @@
     # Files needed by particular GMs
     '../src/utils/debugger/SkDrawCommand.h',
     '../src/utils/debugger/SkDrawCommand.cpp',
     '../src/utils/debugger/SkDebugCanvas.h',
     '../src/utils/debugger/SkDebugCanvas.cpp',
     '../src/utils/debugger/SkObjectParser.h',
     '../src/utils/debugger/SkObjectParser.cpp',
 
   ],
 }