Add CreatePlatformGLTestContext_none.cpp for Google3 build

gyp/gputest.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.
 {
   'targets': [
     {
       'target_name': 'skgputest',
       'product_name': 'skia_skgputest',
       'type': 'static_library',
@@ skipping 67 matching lines @@
           'defines': [
             'GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE=1',
           ],
           'link_settings': {
             'libraries': [
               '-lGLESv2',
               '-lEGL',
             ],
           },
         }],
+        ['skia_os in ["linux", "win", "mac", "chromeos", "android", "ios"]', {
+          'sources/': [ ['exclude', '_none\.(h|cpp)$'],],
+        }],
         ['skia_os != "win"', {
           'sources/': [ ['exclude', '_win\.(h|cpp)$'],],
         }],
         ['skia_os != "mac"', {
           'sources/': [ ['exclude', '_mac\.(h|cpp|m|mm)$'],],
         }],
         ['skia_os != "linux" and skia_os != "chromeos"', {
           'sources/': [ ['exclude', '_glx\.(h|cpp)$'],],
         }],
         ['skia_os != "ios"', {
@@ skipping 15 matching lines @@
             ['exclude', '_angle\.(h|cpp)$'],
           ],
         }],
         [ 'skia_command_buffer == 0', {
           'sources/': [ ['exclude', '_command_buffer\.(h|cpp)$'], ],
         }],
       ],
     },
   ],
 }