[Ozone-DRI] Removing MockDriSurface implementation

ui/ozone/platform/dri/dri.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.
 
 {
   'variables': {
     'internal_ozone_platform_deps': [
       'ozone_platform_dri',
     ],
     'internal_ozone_platform_unittest_deps': [
@@ skipping 80 matching lines @@
         '../../build/linux/system.gyp:dridrm',
         '../../skia/skia.gyp:skia',
         '../gfx/gfx.gyp:gfx_geometry',
       ],
       'direct_dependent_settings': {
         'sources': [
           'dri_surface_factory_unittest.cc',
           'dri_surface_unittest.cc',
           'hardware_display_controller_unittest.cc',
           'screen_manager_unittest.cc',
-          'test/mock_dri_surface.cc',
-          'test/mock_dri_surface.h',
           'test/mock_dri_wrapper.cc',
           'test/mock_dri_wrapper.h',
           'test/mock_surface_generator.cc',
           'test/mock_surface_generator.h',
         ],
       },
     },
   ],
 }