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

Source/core/html/PasswordInputType.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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.
@@ skipping 37 matching lines @@
     return adoptRef(new PasswordInputType(element));
 }
 
 HTMLElement* PasswordInputType::passwordGeneratorButtonElement() const
 {
     return m_generatorButton.get();
 }
 
 bool PasswordInputType::isPasswordGenerationEnabled() const
 {
-    if (Page* page = element()->document()->page())
+    if (Page* page = element()->document().page())
         return page->chrome().client().isPasswordGenerationEnabled();
     return false;
 }
 
 bool PasswordInputType::needsContainer() const
 {
     return BaseTextInputType::needsContainer() || isPasswordGenerationEnabled();
 }
 
 void PasswordInputType::createShadowSubtree()
 {
     BaseTextInputType::createShadowSubtree();
     if (isPasswordGenerationEnabled()) {
-        m_generatorButton = PasswordGeneratorButtonElement::create(element()->document());
+        m_generatorButton = PasswordGeneratorButtonElement::create(&element()->document());
         m_generatorButton->decorate(element());
     }
 }
 
 void PasswordInputType::destroyShadowSubtree()
 {
     BaseTextInputType::destroyShadowSubtree();
     m_generatorButton = 0;
 }
 
@@ skipping 42 matching lines @@
     return true;
 }
 
 bool PasswordInputType::isPasswordField() const
 {
     return true;
 }
 
 void PasswordInputType::enableSecureTextInput()
 {
-    if (element()->document()->frame())
-        element()->document()->setUseSecureKeyboardEntryWhenActive(true);
+    if (element()->document().frame())
+        element()->document().setUseSecureKeyboardEntryWhenActive(true);
 }
 
 void PasswordInputType::disableSecureTextInput()
 {
-    if (element()->document()->frame())
-        element()->document()->setUseSecureKeyboardEntryWhenActive(false);
+    if (element()->document().frame())
+        element()->document().setUseSecureKeyboardEntryWhenActive(false);
 }
 
 } // namespace WebCore