athena: Remove ActivityViewModel::CreateWidget().

athena/content/app_activity.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_H_
 #define ATHENA_CONTENT_APP_ACTIVITY_H_
 
 #include "athena/activity/public/activity.h"
 #include "athena/activity/public/activity_view_model.h"
 #include "athena/content/app_activity_proxy.h"
@@ skipping 27 matching lines @@
   ActivityMediaState GetMediaState() override;
   aura::Window* GetWindow() override;
   content::WebContents* GetWebContents() override;
 
   // ActivityViewModel:
   void Init() override;
   SkColor GetRepresentativeColor() const override;
   base::string16 GetTitle() const override;
   gfx::ImageSkia GetIcon() const override;
   bool UsesFrame() const override;
-  views::Widget* CreateWidget() override;
   views::View* GetContentsView() override;
   gfx::ImageSkia GetOverviewModeImage() override;
   void PrepareContentsForOverview() override;
   void ResetContentsView() override;
 
  protected:
   // Constructor for test.
   explicit AppActivity(const std::string& app_id);
 
   ~AppActivity() override;
@@ skipping 27 matching lines @@
 
   // The content proxy.
   scoped_ptr<ContentProxy> content_proxy_;
 
   DISALLOW_COPY_AND_ASSIGN(AppActivity);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_CONTENT_APP_ACTIVITY_H_