athena: Use ActivityList where appropriate, and fix AppActivity tests.

athena/content/app_activity_registry.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 ATHENA_CONTENT_APP_ACTIVITY_REGISTRY_H_
 #define ATHENA_CONTENT_APP_ACTIVITY_REGISTRY_H_
 
 #include <vector>
 
 #include "athena/activity/public/activity_view_model.h"
@@ skipping 57 matching lines @@
   // When the |AppActivityProxy| gets destroyed it should call this function
   // to disconnect from this object. This call might destroy |this|.
   void ProxyDestroyed(AppActivityProxy* proxy);
 
   // When called by the |AppActivityProxy| to restart the application, it can
   // cause the application to restart. When that happens the proxy will get
   // destroyed. After this call |this| might be destroyed.
   void RestartApplication(AppActivityProxy* proxy);
 
  private:
-  // Called if an unload of an application should take place asynchronously to
-  // avoid object destruction within an observer handler.
-  void DelayedUnload();
-
   // Gets most recently used AppAcitivty that belongs to the same application.
   AppActivity* GetMruActivity();
 
   // A list of all activities associated with this application.
   std::vector<AppActivity*> activity_list_;
 
   // The application id for this proxy.
   std::string app_id_;
 
   // The browser context of the user.
   content::BrowserContext* browser_context_;
 
   // When the activity is unloaded this is the AppActivityProxy. The object is
   // owned the the ActivityManager.
   AppActivityProxy* unloaded_activity_proxy_;
 
   // The presentation values.
   SkColor color_;
   base::string16 title_;
   gfx::ImageSkia image_;
 
   DISALLOW_COPY_AND_ASSIGN(AppActivityRegistry);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_CONTENT_APP_ACTIVITY_REGISTRY_H_