Adding a GYP variable to indicate if a build wants Title Case strings or not....

app/app.gyp

 # Copyright (c) 2009 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': {
     # TODO: remove this helper when we have loops in GYP
     'apply_locales_cmd': ['python', '../chrome/tools/build/apply_locales.py',],
     'chromium_code': 1,
   },
@@ skipping 236 matching lines @@
             'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/app',
           },
           'outputs': [
             '<(SHARED_INTERMEDIATE_DIR)/app/grit/<(RULE_INPUT_ROOT).h',
             # TODO: remove this helper when we have loops in GYP
             '>!@(<(apply_locales_cmd) \'<(SHARED_INTERMEDIATE_DIR)/app/<(RULE_INPUT_ROOT)_ZZLOCALE.pak\' <(locales))',
           ],
           'action': ['python', '<@(_inputs)', '-i', '<(RULE_INPUT_PATH)',
             'build', '-o', '<(grit_out_dir)'],
           'message': 'Generating resources from <(RULE_INPUT_PATH)',
+          'conditions': [
+            ['use_titlecase_in_grd_files==1', {
+              'action': ['-D', 'use_titlecase'],
+            }],
+          ],
         },
       ],
       'sources': [
         # Localizable resources.
         'resources/app_locale_settings.grd',
         'resources/app_strings.grd',
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           '<(SHARED_INTERMEDIATE_DIR)/app',
@@ skipping 82 matching lines @@
                 'process_outputs_as_sources': 1,
                 'message': 'Generating appid information in <(SHARED_INTERMEDIATE_DIR)/chrome/appid.h'
               },
             ],
           },
         ],
       ],
     },
   ],
 }