Implement support for disabling sync through configuration management.

chrome/browser/app_controller_mac.mm

Index: chrome/browser/app_controller_mac.mm
diff --git a/chrome/browser/app_controller_mac.mm b/chrome/browser/app_controller_mac.mm
index 0ed8a0db4562f2ad5788fd6b3449d3c3391455e6..e06cc604b628f1619a7034f37f410d6108a930cd 100644
--- a/chrome/browser/app_controller_mac.mm
+++ b/chrome/browser/app_controller_mac.mm
@@ -634,8 +634,8 @@ void RecordLastRunAppBundlePath() {
                 << "NULL defaultProfile detected -- not doing anything";
             break;
           }
-          enable = ProfileSyncService::IsSyncEnabled() &&
-                   [self keyWindowIsNotModal];
+          enable = defaultProfile->IsSyncAccessible() &&
+              [self keyWindowIsNotModal];
           sync_ui_util::UpdateSyncItem(item, enable, defaultProfile);
           break;
         }
@@ -848,8 +848,7 @@ void RecordLastRunAppBundlePath() {
   menuState_->UpdateCommandEnabled(IDC_HELP_PAGE, true);
   menuState_->UpdateCommandEnabled(IDC_IMPORT_SETTINGS, true);
   menuState_->UpdateCommandEnabled(IDC_REPORT_BUG, true);
-  menuState_->UpdateCommandEnabled(IDC_SYNC_BOOKMARKS,
-                                   ProfileSyncService::IsSyncEnabled());
+  menuState_->UpdateCommandEnabled(IDC_SYNC_BOOKMARKS, true);
   menuState_->UpdateCommandEnabled(IDC_TASK_MANAGER, true);
 }