Move towards event-driven JS on about:sync

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 <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "base/values.h"
+#include "chrome/browser/sync/profile_sync_service_observer.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "sync/js/js_controller.h"
 #include "sync/js/js_event_handler.h"
 #include "sync/js/js_reply_handler.h"
 
 class ProfileSyncService;
 
 // The implementation for the chrome://sync-internals page.
 class SyncInternalsMessageHandler
     : public content::WebUIMessageHandler,
       public syncer::JsEventHandler,
-      public syncer::JsReplyHandler {
+      public syncer::JsReplyHandler,
+      public ProfileSyncServiceObserver {
  public:
   SyncInternalsMessageHandler();
   virtual ~SyncInternalsMessageHandler();
 
   virtual void RegisterMessages() OVERRIDE;
 
+  // Forwards requests to the JsController.
   void ForwardToJsController(const std::string& name, const base::ListValue*);
-  void OnGetAboutInfo(const base::ListValue*);
-  void OnGetListOfTypes(const base::ListValue*);
+
+  // 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);
 
   // syncer::JsEventHandler implementation.
   virtual void HandleJsEvent(
       const std::string& name,
       const syncer::JsEventDetails& details) OVERRIDE;
 
   // syncer::JsReplyHandler implementation.
   virtual void HandleJsReply(
       const std::string& name,
       const syncer::JsArgList& args) OVERRIDE;
 
+  // ProfileSyncServiceObserver implementation.
+  virtual void OnStateChanged() OVERRIDE;
+
  private:
+  // Helper function to register JsController function callbacks.
   void RegisterJsControllerCallback(const std::string& name);
+
+  // Fetches updated aboutInfo and sends it to the page in the form of an
+  // onAboutInfoUpdated event.
+  void SendAboutInfo();
+
   ProfileSyncService* GetProfileSyncService();
 
   base::WeakPtr<syncer::JsController> js_controller_;
   base::WeakPtrFactory<SyncInternalsMessageHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncInternalsMessageHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SYNC_INTERNALS_MESSAGE_HANDLER_H_