Add support for variations controlled overriding UI strings to the variations service.

chrome/chrome_resources.gyp

 # Copyright (c) 2012 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': {
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
     'about_credits_file': '<(SHARED_INTERMEDIATE_DIR)/about_credits.html',
     'additional_modules_list_file': '<(SHARED_INTERMEDIATE_DIR)/chrome/browser/internal/additional_modules_list.txt',
     'omnibox_mojom_file': '<(SHARED_INTERMEDIATE_DIR)/chrome/browser/ui/webui/omnibox/omnibox.mojom.js',
   },
@@ skipping 272 matching lines @@
     },
     {
       # GN version: //chrome/app:make_generated_resources_map
       'target_name': 'chrome_strings_map',
       'type': 'none',
       'dependencies': [ 'chrome_strings', ],
       'actions': [
         {
           'action_name': 'generate_resources_map',
           'inputs': [
+            'browser/metrics/variations/generate_resources_map.py',
             '<(grit_out_dir)/grit/generated_resources.h'
           ],
           'outputs': [
             '<(SHARED_INTERMEDIATE_DIR)/chrome/browser/metrics/variations/generated_resources_map.cc',
           ],
           'action': [
             'python',
             'browser/metrics/variations/generate_resources_map.py',
             '<(grit_out_dir)/grit/generated_resources.h',
             '<(SHARED_INTERMEDIATE_DIR)/chrome/browser/metrics/variations/generated_resources_map.cc'
@@ skipping 256 matching lines @@
                      '<(generator_path)',
                      'credits',
                      '<(about_credits_file)',
           ],
           'message': 'Generating about:credits',
         },
       ],
     },
   ], # targets
 }