Add unit tests target to GN build.

chrome/tools/convert_dict/convert_dict.gyp

 # Copyright 2013 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
+      # GN version: //chrome/tools/convert_dict:lib
       'target_name': 'convert_dict_lib',
       'product_name': 'convert_dict',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
       'include_dirs': [
         '../../../',
       ],
       'dependencies': [
         '../../../base/base.gyp:base',
       ],
@@ skipping 15 matching lines @@
         '../../../base/base.gyp:base_i18n',
         '../../../third_party/hunspell/hunspell.gyp:hunspell',
         'convert_dict_lib',
       ],
       'sources': [
         'convert_dict.cc',
       ],
     },
   ],
 }