Stop using //third_party/khronos headers in SDK

mojo/public/platform/native/BUILD.gn

 # 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.
 
 assert(!defined(is_nacl) || !is_nacl)
 
 import("../../mojo_sdk.gni")
 
 mojo_sdk_source_set("system") {
   sources = [
@@ skipping 78 matching lines @@
     "gles2_impl_oes_vertex_array_object_thunks.cc",
     "gles2_impl_oes_vertex_array_object_thunks.h",
     "gles2_impl_thunks.cc",
     "gles2_impl_thunks.h",
     "gles2_thunks.cc",
     "gles2_thunks.h",
   ]
 
   defines = [ "MOJO_GLES2_IMPLEMENTATION" ]
 
-  configs = [ "//third_party/khronos:khronos_headers" ]
+  configs = [ "../../c/gpu:gpu_configs" ]
 
   mojo_sdk_deps = [
     "mojo/public/c/gles2:headers",
     "mojo/public/c/environment",
     "mojo/public/c/system",
   ]
-
-  if (is_mac) {
-    # TODO(GYP): Make it a run-path dependent library.
-    # 'DYLIB_INSTALL_NAME_BASE': '@loader_path',
-  }
 }
 
 mojo_sdk_source_set("gpu_thunks") {
   sources = []
 }
 
 mojo_sdk_source_set("mgl_thunks") {
   sources = [
     "mgl_thunks.c",
     "mgl_thunks.h",
   ]
 
   mojo_sdk_deps = [ "mojo/public/c/gpu:MGL" ]
 }
 
 mojo_sdk_source_set("mgl_onscreen_thunks") {
   sources = [
     "mgl_onscreen_thunks.c",
     "mgl_onscreen_thunks.h",
   ]
 
   mojo_sdk_deps = [ "mojo/public/c/gpu:MGL_onscreen" ]
 }