Use C++11 features in core/html

Source/core/html/parser/HTMLElementStack.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:
  * 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
@@ skipping 377 matching lines @@
     return m_top.get();
 }
 
 HTMLStackItem* HTMLElementStack::oneBelowTop() const
 {
     // We should never call this if there are fewer than 2 elements on the stack.
     ASSERT(m_top);
     ASSERT(m_top->next());
     if (m_top->next()->stackItem()->isElementNode())
         return m_top->next()->stackItem().get();
-    return 0;
+    return nullptr;
 }
 
 void HTMLElementStack::removeHTMLHeadElement(Element* element)
 {
     ASSERT(m_headElement == element);
     if (m_top->element() == element) {
         popHTMLHeadElement();
         return;
     }
     m_headElement = nullptr;
     removeNonTopCommon(element);
 }
 
 void HTMLElementStack::remove(Element* element)
 {
     ASSERT(!isHTMLHeadElement(element));
     if (m_top->element() == element) {
         pop();
         return;
     }
     removeNonTopCommon(element);
 }
 
 HTMLElementStack::ElementRecord* HTMLElementStack::find(Element* element) const
 {
     for (ElementRecord* pos = m_top.get(); pos; pos = pos->next()) {
         if (pos->node() == element)
             return pos;
     }
-    return 0;
+    return nullptr;
 }
 
 HTMLElementStack::ElementRecord* HTMLElementStack::topmost(const AtomicString& tagName) const
 {
     for (ElementRecord* pos = m_top.get(); pos; pos = pos->next()) {
         if (pos->stackItem()->matchesHTMLTag(tagName))
             return pos;
     }
-    return 0;
+    return nullptr;
 }
 
 bool HTMLElementStack::contains(Element* element) const
 {
     return !!find(element);
 }
 
 bool HTMLElementStack::contains(const AtomicString& tagName) const
 {
     return !!topmost(tagName);
@@ skipping 158 matching lines @@
 HTMLElementStack::ElementRecord* HTMLElementStack::furthestBlockForFormattingElement(Element* formattingElement) const
 {
     ElementRecord* furthestBlock = 0;
     for (ElementRecord* pos = m_top.get(); pos; pos = pos->next()) {
         if (pos->element() == formattingElement)
             return furthestBlock;
         if (pos->stackItem()->isSpecialNode())
             furthestBlock = pos;
     }
     ASSERT_NOT_REACHED();
-    return 0;
+    return nullptr;
 }
 
 void HTMLElementStack::trace(Visitor* visitor)
 {
     visitor->trace(m_top);
     visitor->trace(m_rootNode);
     visitor->trace(m_headElement);
     visitor->trace(m_bodyElement);
 }
 
 #ifndef NDEBUG
 
 void HTMLElementStack::show()
 {
     for (ElementRecord* record = m_top.get(); record; record = record->next())
         record->element()->showNode();
 }
 
 #endif
 
 }