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

chrome/browser/ui/webui/sync_internals_message_handler.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_MESSAGE_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_MESSAGE_HANDLER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 50 matching lines @@
 
   // Fires an event to send updated info back to the page.
   void HandleRequestUpdatedAboutInfo(const base::ListValue* args);
 
   // Fires and event to send the list of types back to the page.
   void HandleRequestListOfTypes(const base::ListValue* args);
 
   // Handler for getAllNodes message.  Needs a |request_id| argument.
   void HandleGetAllNodes(const base::ListValue* args);
 
+  // Handler for requests to get UserEvents tab visibility.
+  void HandleRequestUserEventsVisibility(const base::ListValue* args);
+
+  // Handler for writeUserEvent message.
+  void HandleWriteUserEvent(const base::ListValue* args);
+
   // syncer::JsEventHandler implementation.
   void HandleJsEvent(const std::string& name,
                      const syncer::JsEventDetails& details) override;
 
   // Callback used in GetAllNodes.
   void OnReceivedAllNodes(int request_id,
                           std::unique_ptr<base::ListValue> nodes);
 
   // syncer::SyncServiceObserver implementation.
   void OnStateChanged(syncer::SyncService* sync) override;
@@ skipping 41 matching lines @@
 
   // An abstraction of who creates the about sync info value map.
   std::unique_ptr<AboutSyncDataExtractor> about_sync_data_extractor_;
 
   base::WeakPtrFactory<SyncInternalsMessageHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncInternalsMessageHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_MESSAGE_HANDLER_H_