Exclude chrome/common/extensions/api/ from build if enable_extensions==0

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',
     'repack_locales_cmd': ['python', 'tools/build/repack_locales.py'],
   },
   'targets': [
     {
@@ skipping 105 matching lines @@
         },
         {
           'action_name': 'renderer_resources',
           'variables': {
             'grit_grd_file': 'renderer/resources/renderer_resources.grd',
           },
           'includes': [ '../build/grit_action.gypi' ],
         },
       ],
       'conditions': [
-        ['OS != "ios"', {
+        ['enable_extensions==1', {
           'actions': [
             {
               'action_name': 'extensions_api_resources',
               'variables': {
                 'grit_grd_file': 'common/extensions_api_resources.grd',
               },
               'includes': [ '../build/grit_action.gypi' ],
             }
           ],
         }],
@@ skipping 287 matching lines @@
           'variables': {
             'grit_grd_file': 'app/theme/chrome_unscaled_resources.grd',
           },
           'includes': [ '../build/grit_action.gypi' ],
         },
       ],
       'includes': [ '../build/grit_target.gypi' ],
     },
   ], # targets
 }