Add initial implementation of cc::Surfaces backend for exo.

components/exo.gypi

 # Copyright 2015 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: //components/exo
       'target_name': 'exo',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../ash/ash.gyp:ash',
         '../base/base.gyp:base',
         '../cc/cc.gyp:cc',
+        '../cc/cc.gyp:cc_surfaces',
         '../gpu/gpu.gyp:gpu',
         '../skia/skia.gyp:skia',
         '../ui/aura/aura.gyp:aura',
         '../ui/compositor/compositor.gyp:compositor',
         '../ui/gfx/gfx.gyp:gfx',
         '../ui/gfx/gfx.gyp:gfx_geometry',
         '../ui/gl/gl.gyp:gl',
         '../ui/views/views.gyp:views',
         '../ui/wm/wm.gyp:wm',
       ],
@@ skipping 78 matching lines @@
               'defines': [
                 'USE_XKBCOMMON',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }