Delay string conversion of attribute names until needed.

Source/core/inspector/InspectorInstrumentation.idl

 /*
 * Copyright (C) 2013 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 69 matching lines @@
     [DOM, DOMDebugger, Inline=FastReturn]
     void didInsertDOMNode([Keep] Node*);
 
     [DOMDebugger, DOM, Inline=FastReturn]
     void willRemoveDOMNode([Keep] Node*);
 
     [DOMDebugger, DOM, Inline=FastReturn]
     void willModifyDOMAttr([Keep] Element*, const AtomicString& oldValue, const AtomicString& newValue);
 
     [DOM, Inline=FastReturn]
-    void didModifyDOMAttr([Keep] Element*, const String& name, const AtomicString& value);
+    void didModifyDOMAttr([Keep] Element*, const QualifiedName& name, const AtomicString& value);
 
     [DOM, Inline=FastReturn]
-    void didRemoveDOMAttr([Keep] Element*, const String& name);
+    void didRemoveDOMAttr([Keep] Element*, const QualifiedName& name);
 
     [DOM, Inline=FastReturn]
     void characterDataModified([Keep] CharacterData*);
 
     [DOM, DOMDebugger, Inline=FastReturn]
     void didInvalidateStyleAttr([Keep] Node*);
 
     [DOM, Inline=FastReturn]
     void didPerformElementShadowDistribution([Keep] Element*);
 
@@ skipping 423 matching lines @@
 interface InspectorCanvasInstrumentation {
 
 #include "bindings/core/v8/ScriptValue.h"
 
     [Canvas]
     ScriptValue wrapCanvas2DRenderingContextForInstrumentation(Document*, const ScriptValue&);
 
     [Canvas]
     ScriptValue wrapWebGLRenderingContextForInstrumentation(Document*, const ScriptValue&);
 }