[Sync] Add a simple UI to sync-internals to create UserEvents.

chrome/browser/ui/webui/sync_internals_ui.cc

Index: chrome/browser/ui/webui/sync_internals_ui.cc
diff --git a/chrome/browser/ui/webui/sync_internals_ui.cc b/chrome/browser/ui/webui/sync_internals_ui.cc
index 39a45f09e45ffc0197830e9f6c0bb91fd59b0c62..97763c58b0e6101fe9b65ae3ac3e1daaf8fd12fb 100644
--- a/chrome/browser/ui/webui/sync_internals_ui.cc
+++ b/chrome/browser/ui/webui/sync_internals_ui.cc
@@ -40,6 +40,8 @@ content::WebUIDataSource* CreateSyncInternalsHTMLSource() {
                           IDR_SYNC_DRIVER_SYNC_INTERNALS_EVENTS_JS);
   source->AddResourcePath(syncer::sync_ui_util::kSearchJS,
                           IDR_SYNC_DRIVER_SYNC_INTERNALS_SEARCH_JS);
+  source->AddResourcePath(syncer::sync_ui_util::kUserEventsJS,
+                          IDR_SYNC_DRIVER_SYNC_INTERNALS_USER_EVENTS_JS);
   source->SetDefaultResource(IDR_SYNC_DRIVER_SYNC_INTERNALS_INDEX_HTML);
   return source;
 }