gpu/khronos_glcts_support: add support for GN builds

gpu/khronos_glcts_support/khronos_glcts_test.gyp

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'includes': [
     'khronos_glcts.gypi',
+    'khronos_glcts_defaults.gypi',
   ],
   'targets': [
     {
       'target_name': 'khronos_glcts_test',
       'type': 'executable',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/gpu/gpu.gyp:gpu',
         '<(DEPTH)/testing/gtest.gyp:gtest',
       ],
@@ skipping 74 matching lines @@
             '<(DEPTH)/third_party/khronos_glcts/cts/glcTestPackageEntry.cpp',
             '<(DEPTH)/third_party/khronos_glcts/cts/glcTestPackageRegistry.cpp',
             '<(DEPTH)/third_party/khronos_glcts/cts/glcTestPackageRegistry.hpp',
             'native/main.cc',
           ],
         },
       ],
     }],
   ],
 }