WidgetDelegateView is its own contents view.

mash/login/login.cc

 // Copyright 2016 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.
 
 #include "mash/login/login.h"
 
 #include <map>
 #include <memory>
 
 #include "ash/public/interfaces/container.mojom.h"
@@ skipping 62 matching lines @@
     AddChildView(login_button_1_);
     AddChildView(login_button_2_);
   }
   ~UI() override {
     // Prevent the window manager from restarting during graceful shutdown.
     mash_wm_connection_->SetConnectionLostClosure(base::Closure());
     base::MessageLoop::current()->QuitWhenIdle();
   }
 
   // Overridden from views::WidgetDelegate:
-  views::View* GetContentsView() override { return this; }
   base::string16 GetWindowTitle() const override {
     // TODO(beng): use resources.
     return base::ASCIIToUTF16("Login");
   }
   void DeleteDelegate() override { delete this; }
 
   // Overridden from views::View:
   void Layout() override {
     gfx::Rect button_box = GetLocalBounds();
     button_box.Inset(10, 10);
@@ skipping 106 matching lines @@
 }
 
 }  // namespace
 
 shell::Service* CreateLogin() {
   return new Login;
 }
 
 }  // namespace login
 }  // namespace main