Pass implementation object to supplemental classes by reference

Source/core/page/DOMWindowPagePopup.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
 DOMWindowPagePopup::~DOMWindowPagePopup()
 {
     m_controller->clearPagePopupClient();
 }
 
 const char* DOMWindowPagePopup::supplementName()
 {
     return "DOMWindowPagePopup";
 }
 
-PagePopupController* DOMWindowPagePopup::pagePopupController(DOMWindow* window)
+PagePopupController* DOMWindowPagePopup::pagePopupController(DOMWindow& window)
 {
-    DOMWindowPagePopup* supplement = static_cast<DOMWindowPagePopup*>(from(window, supplementName()));
+    DOMWindowPagePopup* supplement = static_cast<DOMWindowPagePopup*>(from(&window, supplementName()));
     ASSERT(supplement);
     return supplement->m_controller.get();
 }
 
-void DOMWindowPagePopup::install(DOMWindow* window, PagePopupClient* popupClient)
+void DOMWindowPagePopup::install(DOMWindow& window, PagePopupClient* popupClient)
 {
-    ASSERT(window);
     ASSERT(popupClient);
     provideTo(window, supplementName(), adoptPtr(new DOMWindowPagePopup(popupClient)));
 }
 
-void DOMWindowPagePopup::uninstall(DOMWindow* window)
+void DOMWindowPagePopup::uninstall(DOMWindow& window)
 {
-    ASSERT(window);
-    window->removeSupplement(supplementName());
+    window.removeSupplement(supplementName());
 }
 
 }