Expose CHROMIUM_texture_mailbox/sync_point stubs in mojo public headers

mojo/mojo_public.gypi

 # 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.
 
 {
   'targets': [
     {
       # GN version: //mojo/public/c/system
       'target_name': 'mojo_system',
       'type': 'static_library',
@@ skipping 63 matching lines @@
               '-Wl,--exclude-libs=ALL',
             ],
           }],
         ],
       },
       'sources': [
         'public/c/gles2/gles2.h',
         'public/c/gles2/gles2_export.h',
         'public/platform/native/gles2_thunks.cc',
         'public/platform/native/gles2_thunks.h',
+        'public/platform/native/gles2_impl_thunks.cc',
+        'public/platform/native/gles2_impl_thunks.h',
+        'public/platform/native/gles2_impl_chromium_texture_mailbox_thunks.cc',
+        'public/platform/native/gles2_impl_chromium_texture_mailbox_thunks.h',
+        'public/platform/native/gles2_impl_chromium_sync_point_thunks.cc',
+        'public/platform/native/gles2_impl_chromium_sync_point_thunks.h',
       ],
     },
     {
       # GN version: //mojo/public/cpp/bindings
       'target_name': 'mojo_cpp_bindings',
       'type': 'static_library',
       'include_dirs': [
         '..'
       ],
       'sources': [
@@ skipping 192 matching lines @@
           },
           'dependencies': [
             'mojo_public_java',
           ],
           'includes': [ '../build/java.gypi' ],
         },
       ],
     }],
   ],
 }