Make sure getAttribute() / setAttribute() callers use AtomicStrings

Source/core/editing/markup.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. 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
@@ skipping 65 matching lines @@
     {
     }
 
     AttributeChange(PassRefPtr<Element> element, const QualifiedName& name, const String& value)
         : m_element(element), m_name(name), m_value(value)
     {
     }
 
     void apply()
     {
-        m_element->setAttribute(m_name, m_value);
+        m_element->setAttribute(m_name, AtomicString(m_value));
     }
 
 private:
     RefPtr<Element> m_element;
     QualifiedName m_name;
     String m_value;
 };
 
 static void completeURLs(DocumentFragment& fragment, const String& baseURL)
 {
@@ skipping 985 matching lines @@
         return;
 
     RefPtr<Text> textNode = toText(node.get());
     RefPtr<Text> textNext = toText(next);
     textNode->appendData(textNext->data());
     if (textNext->parentNode()) // Might have been removed by mutation event.
         textNext->remove(exceptionState);
 }
 
 }