New build flag system, convert Google Now flag

chrome/common_constants.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': {
     'chromium_code': 1,
     'common_constants_sources': [
       'common/chrome_constants.cc',
       'common/chrome_constants.h',
@@ skipping 54 matching lines @@
             '<@(_outputs)',
           ],
           'message': 'Generating version header file: <@(_outputs)',
         },
       ],
     },
     {
       # GN version: //chrome/common:constants
       'target_name': 'common_constants',
       'type': 'static_library',
+      'hard_dependency': 1,  # Because of transitive dep on version_header.
       'sources': [
         '<@(common_constants_sources)'
       ],
       'include_dirs': [
         '<(SHARED_INTERMEDIATE_DIR)',  # Needed by chrome_paths.cc.
       ],
       'dependencies': [
         'version_header',
         '../base/base.gyp:base',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
@@ skipping 44 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }