Cleanup GrContextFactory and make it's subclasses private

gyp/tools.gyp

 # GYP file to build various tools.
 #
 # To build on Linux:
 #  ./gyp_skia tools.gyp && make tools
 #
 {
   'includes': [
     'apptype_console.gypi',
   ],
   'targets': [
@@ skipping 455 matching lines @@
       ],
       'conditions': [
         ['skia_gpu == 1',
           {
             'include_dirs' : [
               '../src/gpu',
             ],
             'dependencies': [
               'gputest.gyp:skgputest',
             ],
+            'export_dependent_settings': [
+                'gputest.gyp:skgputest',
+            ],
           },
         ],
       ],
     },
     {
       'target_name': 'render_pdfs',
       'type': 'executable',
       'sources': [
         '../tools/render_pdfs_main.cpp',
       ],
@@ skipping 220 matching lines @@
               'flags.gyp:flags',
               'skia_lib.gyp:skia_lib',
               'resources',
             ],
           },
         ],
       },
     ],
   ],
 }