Have Node::document() return a reference instead of a pointer

Source/core/html/HTMLPlugInElement.cpp

 /**
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 75 matching lines @@
         if (Widget* widget = renderer->widget())
             widget->eventListenersRemoved();
     }
 }
 
 void HTMLPlugInElement::detach(const AttachContext& context)
 {
     m_instance.clear();
 
     if (m_isCapturingMouseEvents) {
-        if (Frame* frame = document()->frame())
+        if (Frame* frame = document().frame())
             frame->eventHandler()->setCapturingMouseEventsNode(0);
         m_isCapturingMouseEvents = false;
     }
 
     if (m_NPObject) {
         _NPN_ReleaseObject(m_NPObject);
         m_NPObject = 0;
     }
 
     HTMLFrameOwnerElement::detach(context);
 }
 
 void HTMLPlugInElement::resetInstance()
 {
     m_instance.clear();
 }
 
 PassScriptInstance HTMLPlugInElement::getInstance()
 {
-    Frame* frame = document()->frame();
+    Frame* frame = document().frame();
     if (!frame)
         return 0;
 
     // If the host dynamically turns off JavaScript (or Java) we will still return
     // the cached allocated Bindings::Instance.  Not supporting this edge-case is OK.
     if (m_instance)
         return m_instance;
 
     if (Widget* widget = pluginWidget())
         m_instance = frame->script()->createScriptInstanceForWidget(widget);
@@ skipping 77 matching lines @@
     if (!widget)
         return;
     widget->handleEvent(event);
     if (event->defaultHandled())
         return;
     HTMLFrameOwnerElement::defaultEventHandler(event);
 }
 
 RenderWidget* HTMLPlugInElement::renderWidgetForJSBindings() const
 {
-    document()->updateLayoutIgnorePendingStylesheets();
+    document().updateLayoutIgnorePendingStylesheets();
     return existingRenderWidget();
 }
 
 bool HTMLPlugInElement::isKeyboardFocusable() const
 {
-    if (!document()->page())
+    if (!document().page())
         return false;
 
     const PluginView* plugin = pluginWidget() && pluginWidget()->isPluginView() ? static_cast<const PluginView*>(pluginWidget()) : 0;
     if (plugin)
         return plugin->supportsKeyboardFocus();
 
     return false;
 }
 
 bool HTMLPlugInElement::isPluginElement() const
 {
     return true;
 }
 
 bool HTMLPlugInElement::rendererIsFocusable() const
 {
     if (HTMLFrameOwnerElement::supportsFocus() && HTMLFrameOwnerElement::rendererIsFocusable())
         return true;
 
     if (useFallbackContent() || !renderer() || !renderer()->isEmbeddedObject())
         return false;
     return !toRenderEmbeddedObject(renderer())->showsUnavailablePluginIndicator();
 }
 
 NPObject* HTMLPlugInElement::getNPObject()
 {
-    ASSERT(document()->frame());
+    ASSERT(document().frame());
     if (!m_NPObject)
-        m_NPObject = document()->frame()->script()->createScriptObjectForPluginElement(this);
+        m_NPObject = document().frame()->script()->createScriptObjectForPluginElement(this);
     return m_NPObject;
 }
 
 }