Default GR_GL_FUNCTION_TYPE to __stdcall on Windows.

gyp/gpu.gyp

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 # GYP for building gpu
 {
   'target_defaults': {
     'conditions': [
       ['skia_os != "win"', {
         'sources/': [ ['exclude', '_win.(h|cpp)$'],
@@ skipping 47 matching lines @@
           'defines/': [
             ['exclude', '.*'],
           ],
           'include_dirs/': [
             ['exclude', '.*'],
           ],
         },
       }],
     ],
     'direct_dependent_settings': {
-      'conditions': [
-        [ 'skia_os == "win"', {
-          'defines': [
-            'GR_GL_FUNCTION_TYPE=__stdcall',
-          ],
-        }],
-      ],
       'include_dirs': [
         '../include/gpu',
       ],
     },
   },
   'targets': [
     {
       'target_name': 'skgpu',
       'product_name': 'skia_skgpu',
       'type': 'static_library',
@@ skipping 159 matching lines @@
                   '../tools/viewer/sk_app/android',
                 ],
               },
               'dependencies!': [
                 'shaderc.gyp:shaderc_combined',
               ],
               'sources': [
                 # the gyp -> android.mk generator doesn't seem to like cpp files
                 # in directories outside of src, bench, or dm.  Until this gets fixed
                 # I just start the path in the src directory.
-                '<(skia_src_path)/../tools/viewer/sk_app/WindowContext.cpp', 
+                '<(skia_src_path)/../tools/viewer/sk_app/WindowContext.cpp',
                 '<(skia_src_path)/../tools/viewer/sk_app/VulkanWindowContext.cpp',
                 '<(skia_src_path)/../tools/viewer/sk_app/android/VulkanWindowContext_android.cpp'
               ],
             }],
           ],
         }, {
           'sources!': [
             '<@(skgpu_vk_sources)',
           ],
         }],
       ],
     },
   ],
 }