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

Source/core/html/RadioInputType.cpp

 /*
  * Copyright (C) 2005, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 57 matching lines @@
         return;
     const String& key = event->keyIdentifier();
     if (key != "Up" && key != "Down" && key != "Left" && key != "Right")
         return;
 
     // Left and up mean "previous radio button".
     // Right and down mean "next radio button".
     // Tested in WinIE, and even for RTL, left still means previous radio button (and so moves
     // to the right).  Seems strange, but we'll match it.
     // However, when using Spatial Navigation, we need to be able to navigate without changing the selection.
-    Document* document = element()->document();
-    if (isSpatialNavigationEnabled(document->frame()))
+    Document& document = element()->document();
+    if (isSpatialNavigationEnabled(document.frame()))
         return;
     bool forward = (key == "Down" || key == "Right");
 
     // We can only stay within the form's children if the form hasn't been demoted to a leaf because
     // of malformed HTML.
     Node* node = element();
     while ((node = (forward ? NodeTraversal::next(node) : NodeTraversal::previous(node)))) {
         // Once we encounter a form element, we know we're through.
         if (node->hasTagName(formTag))
             break;
         // Look for more radio buttons.
         if (!node->hasTagName(inputTag))
             continue;
         HTMLInputElement* inputElement = toHTMLInputElement(node);
         if (inputElement->form() != element()->form())
             break;
         if (inputElement->isRadioButton() && inputElement->name() == element()->name() && inputElement->isFocusable()) {
             RefPtr<HTMLInputElement> protector(inputElement);
-            document->setFocusedElement(inputElement);
+            document.setFocusedElement(inputElement);
             inputElement->dispatchSimulatedClick(event, SendNoEvents, DoNotShowPressedLook);
             event->setDefaultHandled();
             return;
         }
     }
 }
 
 void RadioInputType::handleKeyupEvent(KeyboardEvent* event)
 {
     const String& key = event->keyIdentifier();
     if (key != "U+0020")
         return;
     // If an unselected radio is tabbed into (because the entire group has nothing
     // checked, or because of some explicit .focus() call), then allow space to check it.
     if (element()->checked())
         return;
     dispatchSimulatedClickIfActive(event);
 }
 
 bool RadioInputType::isKeyboardFocusable() const
 {
     if (!InputType::isKeyboardFocusable())
         return false;
 
     // When using Spatial Navigation, every radio button should be focusable.
-    if (isSpatialNavigationEnabled(element()->document()->frame()))
+    if (isSpatialNavigationEnabled(element()->document().frame()))
         return true;
 
     // Never allow keyboard tabbing to leave you in the same radio group.  Always
     // skip any other elements in the group.
-    Element* currentFocusedElement = element()->document()->focusedElement();
+    Element* currentFocusedElement = element()->document().focusedElement();
     if (currentFocusedElement && currentFocusedElement->hasTagName(inputTag)) {
         HTMLInputElement* focusedInput = toHTMLInputElement(currentFocusedElement);
         if (focusedInput->isRadioButton() && focusedInput->form() == element()->form() && focusedInput->name() == element()->name())
             return false;
     }
 
     // Allow keyboard focus if we're checked or if nothing in the group is checked.
     return element()->checked() || !element()->checkedRadioButtonForGroup();
 }
 
@@ skipping 44 matching lines @@
 {
     return true;
 }
 
 bool RadioInputType::supportsIndeterminateAppearance() const
 {
     return false;
 }
 
 } // namespace WebCore