Consistently use AtomicString for namespaceURI / prefix

Source/bindings/v8/custom/V8CustomXPathNSResolver.cpp

 // Copyright (c) 2008, 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 40 matching lines @@
 V8CustomXPathNSResolver::V8CustomXPathNSResolver(v8::Handle<v8::Object> resolver, v8::Isolate* isolate)
     : m_resolver(resolver)
     , m_isolate(isolate)
 {
 }
 
 V8CustomXPathNSResolver::~V8CustomXPathNSResolver()
 {
 }
 
-String V8CustomXPathNSResolver::lookupNamespaceURI(const String& prefix)
+AtomicString V8CustomXPathNSResolver::lookupNamespaceURI(const String& prefix)
 {
     v8::Handle<v8::Function> lookupNamespaceURIFunc;
     v8::Handle<v8::String> lookupNamespaceURIName = v8AtomicString(m_isolate, "lookupNamespaceURI");
 
     // Check if the resolver has a function property named lookupNamespaceURI.
     if (m_resolver->Has(lookupNamespaceURIName)) {
         v8::Handle<v8::Value> lookupNamespaceURI = m_resolver->Get(lookupNamespaceURIName);
         if (lookupNamespaceURI->IsFunction())
             lookupNamespaceURIFunc = v8::Handle<v8::Function>::Cast(lookupNamespaceURI);
     }
 
     if (lookupNamespaceURIFunc.IsEmpty() && !m_resolver->IsFunction()) {
         Frame* frame = activeDOMWindow()->frame();
         if (frame && frame->page())
             frame->page()->console().addMessage(JSMessageSource, ErrorMessageLevel, "XPathNSResolver does not have a lookupNamespaceURI method.");
-        return String();
+        return nullAtom;
     }
 
     // Catch exceptions from calling the namespace resolver.
     v8::TryCatch tryCatch;
     tryCatch.SetVerbose(true); // Print exceptions to console.
 
     const int argc = 1;
     v8::Handle<v8::Value> argv[argc] = { v8String(m_isolate, prefix) };
     v8::Handle<v8::Function> function = lookupNamespaceURIFunc.IsEmpty() ? v8::Handle<v8::Function>::Cast(m_resolver) : lookupNamespaceURIFunc;
 
     v8::Handle<v8::Value> retval = ScriptController::callFunction(activeExecutionContext(), function, m_resolver, argc, argv, m_isolate);
 
     // Eat exceptions from namespace resolver and return an empty string. This will most likely cause NamespaceError.
     if (tryCatch.HasCaught())
-        return String();
+        return nullAtom;
 
-    return toWebCoreStringWithNullCheck(retval);
+    V8TRYCATCH_FOR_V8STRINGRESOURCE_RETURN(V8StringResource<WithNullCheck>, returnString, retval, nullAtom);
+    return returnString;
 }
 
 } // namespace WebCore