reenable vertices gm, adding picture support

gyp/gmslides.gypi

 # include this gypi to include all the golden master slides.
 {
   'sources': [
     '../gm/aaclip.cpp',
     '../gm/aarectmodes.cpp',
     '../gm/alphagradients.cpp',
     '../gm/androidfallback.cpp',
     '../gm/arcofzorro.cpp',
     '../gm/arithmode.cpp',
     '../gm/beziereffects.cpp',
@@ skipping 125 matching lines @@
     '../gm/testimagefilters.cpp',
     '../gm/texdata.cpp',
     '../gm/thinrects.cpp',
     '../gm/thinstrokedrects.cpp',
     '../gm/tileimagefilter.cpp',
     '../gm/tilemodes.cpp',
     '../gm/tilemodes_scaled.cpp',
     '../gm/tinybitmap.cpp',
     '../gm/twopointradial.cpp',
     '../gm/typeface.cpp',
-#    '../gm/vertices.cpp',
+    '../gm/vertices.cpp',
     '../gm/verttext.cpp',
     '../gm/verttext2.cpp',
     '../gm/verylargebitmap.cpp',
     '../gm/xfermodeimagefilter.cpp',
     '../gm/xfermodes.cpp',
     '../gm/xfermodes2.cpp',
     '../gm/xfermodes3.cpp',
   ],
 }