add a GM case to ensure path effect for big filled/stroked text is correctly rendered

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 104 matching lines @@
     '../gm/mixedxfermodes.cpp',
     '../gm/modecolorfilters.cpp',
     '../gm/morphology.cpp',
     '../gm/nested.cpp',
     '../gm/ninepatchstretch.cpp',
     '../gm/nonclosedpaths.cpp',
     '../gm/offsetimagefilter.cpp',
     '../gm/optimizations.cpp',
     '../gm/ovals.cpp',
     '../gm/patheffects.cpp',
+    '../gm/patheffect4bigtext.cpp',
     '../gm/pathfill.cpp',
     '../gm/pathinterior.cpp',
     '../gm/pathopsinverse.cpp',
     '../gm/pathopsskpclip.cpp',
     '../gm/pathreverse.cpp',
     '../gm/peekpixels.cpp',
     '../gm/perlinnoise.cpp',
     '../gm/pictureimagefilter.cpp',
     '../gm/pictureshader.cpp',
     '../gm/points.cpp',
@@ skipping 88 matching lines @@
         # fulfilling. See http://skbug.com/1978
         '../gm/verylargebitmap.cpp',
       ],
 
       'sources': [
         '../gm/androidfallback.cpp',
       ],
     }],
   ],
 }