Include sync.pb.h in sync_data.h.

chrome/chrome_browser_extensions.gypi

 # Copyright (c) 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.
 
 {
   'targets': [
     {
       'target_name': 'browser_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 46 matching lines @@
         '../ui/resources/ui_resources.gyp:ui_resources',
         '../url/url.gyp:url_lib',
         '../webkit/storage_browser.gyp:webkit_storage_browser',
         '../webkit/storage_common.gyp:webkit_storage_common',
         '../webkit/webkit_resources.gyp:webkit_resources',
       ],
       'include_dirs': [
         '..',
         '<(INTERMEDIATE_DIR)',
       ],
+      # This target has header files that include generated header files from
+      # sync. Give our dependents access to those headers.
       'export_dependent_settings': [
         '../content/content.gyp:content_browser',
+        '../sync/sync.gyp:sync',
       ],
       'sources': [
         # All .cc, .h, .m, and .mm files under browser/extensions except for
         # tests and mocks.
         'browser/apps/app_launch_for_metro_restart_win.cc',
         'browser/apps/app_launch_for_metro_restart_win.h',
         'browser/apps/app_url_redirector.cc',
         'browser/apps/app_url_redirector.h',
         'browser/apps/chrome_apps_client.cc',
         'browser/apps/chrome_apps_client.h',
@@ skipping 1117 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/chromeos/contacts',
             'proto_out_dir': 'chrome/browser/chromeos/contacts',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],  # 'chromeos=1'
   ],  # 'conditions'
 }