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

Source/core/html/BaseChooserOnlyDateAndTimeInputType.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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 31 matching lines @@
     closeDateTimeChooser();
 }
 
 void BaseChooserOnlyDateAndTimeInputType::handleDOMActivateEvent(Event*)
 {
     if (element()->isDisabledOrReadOnly() || !element()->renderer() || !ScriptController::processingUserGesture())
         return;
 
     if (m_dateTimeChooser)
         return;
-    if (!element()->document()->page())
+    if (!element()->document().page())
         return;
     DateTimeChooserParameters parameters;
     if (!element()->setupDateTimeChooserParameters(parameters))
         return;
-    m_dateTimeChooser = element()->document()->page()->chrome().openDateTimeChooser(this, parameters);
+    m_dateTimeChooser = element()->document().page()->chrome().openDateTimeChooser(this, parameters);
 }
 
 void BaseChooserOnlyDateAndTimeInputType::createShadowSubtree()
 {
     DEFINE_STATIC_LOCAL(AtomicString, valueContainerPseudo, ("-webkit-date-and-time-value", AtomicString::ConstructFromLiteral));
 
-    RefPtr<HTMLDivElement> valueContainer = HTMLDivElement::create(element()->document());
+    RefPtr<HTMLDivElement> valueContainer = HTMLDivElement::create(&element()->document());
     valueContainer->setPart(valueContainerPseudo);
     element()->userAgentShadowRoot()->appendChild(valueContainer.get());
     updateAppearance();
 }
 
 void BaseChooserOnlyDateAndTimeInputType::updateAppearance()
 {
     Node* node = element()->userAgentShadowRoot()->firstChild();
     if (!node || !node->isHTMLElement())
         return;
@@ skipping 49 matching lines @@
 }
 
 void BaseChooserOnlyDateAndTimeInputType::accessKeyAction(bool sendMouseEvents)
 {
     BaseDateAndTimeInputType::accessKeyAction(sendMouseEvents);
     BaseClickableWithKeyInputType::accessKeyAction(element(), sendMouseEvents);
 }
 
 }
 #endif