Refactor how we handle resources path in Tests.

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',
+    '../tools',
   ],
   'sources': [
     # base class for GMs
     '../gm/gm.cpp',
     '../gm/gm.h',
 
     '../gm/aaclip.cpp',
     '../gm/aarectmodes.cpp',
     '../gm/alphagradients.cpp',
     '../gm/arcofzorro.cpp',
@@ skipping 207 matching lines @@
         # fulfilling. See http://skbug.com/1978
         '../gm/verylargebitmap.cpp',
       ],
 
       'sources': [
         '../gm/androidfallback.cpp',
       ],
     }],
   ],
 }