Rationalize dependency on khronos EGL headers in place of angle.

gpu/command_buffer_service.gypi

 # Copyright (c) 2012 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.
 
 {
   'include_dirs': [
     '..',
   ],
   'all_dependent_settings': {
     'include_dirs': [
@@ skipping 98 matching lines @@
     'command_buffer/service/vertex_attrib_manager.cc',
   ],
   'conditions': [
     ['toolkit_uses_gtk == 1', {
       'dependencies': [
         '../build/linux/system.gyp:gtk',
       ],
     }],
     ['ui_compositor_image_transport==1', {
       'include_dirs': [
-        '../third_party/angle/include',
+        '../third_party/khronos',
       ],
     }],
   ],
 }