[SyncFS] Make GetOriginStatusMap asynchronous

chrome/browser/ui/webui/sync_file_system_internals/extension_statuses_handler.h

 // Copyright 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_EXTENSION_STATUSES_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_EXTENSION_STATUSES_HANDLER_H_
 
 #include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 class Profile;
 
 namespace syncfs_internals {
 
 // This class handles message from WebUI page of chrome://syncfs-internals/
 // for the Extension Statuses tab. It corresponds to browser/resources/
 // sync_file_system_internals/extension_statuses.html. All methods in this class
 // should be called on UI thread.
 class ExtensionStatusesHandler : public content::WebUIMessageHandler {
  public:
   explicit ExtensionStatusesHandler(Profile* profile);
   virtual ~ExtensionStatusesHandler();
 
   // Shared by Extension Statuses Tab and also File Metadata Tab to generate the
   // extension drop down.
-  static void GetExtensionStatusesAsDictionary(Profile* profile,
-                                               base::ListValue* values);
+  static void GetExtensionStatusesAsDictionary(
+      Profile* profile,
+      const base::Callback<void(const base::ListValue&)>& callback);
 
   // WebUIMessageHandler implementation.
   virtual void RegisterMessages() OVERRIDE;
 
  private:
   void GetExtensionStatuses(const base::ListValue* args);
+  void DidGetExtensionStatuses(const base::ListValue& list);
 
   Profile* profile_;
+  base::WeakPtrFactory<ExtensionStatusesHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionStatusesHandler);
 };
 
 }  // namespace syncfs_internals
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_EXTENSION_STATUSES_HANDLER_H_