Have Document::parseQualifiedName() deal with AtomicStrings

Source/core/dom/DOMImplementation.cpp

Index: Source/core/dom/DOMImplementation.cpp
diff --git a/Source/core/dom/DOMImplementation.cpp b/Source/core/dom/DOMImplementation.cpp
index 33efde51610da46c82bbf76ac0842c31ca9ddf09..ff898a52dea55fc0f6fe0adb3536cf06815d005b 100644
--- a/Source/core/dom/DOMImplementation.cpp
+++ b/Source/core/dom/DOMImplementation.cpp
@@ -178,10 +178,10 @@ bool DOMImplementation::hasFeature(const String& feature, const String& version)
     return true;
 }
 
-PassRefPtr<DocumentType> DOMImplementation::createDocumentType(const String& qualifiedName,
+PassRefPtr<DocumentType> DOMImplementation::createDocumentType(const AtomicString& qualifiedName,
     const String& publicId, const String& systemId, ExceptionState& exceptionState)
 {
-    String prefix, localName;
+    AtomicString prefix, localName;
     if (!Document::parseQualifiedName(qualifiedName, prefix, localName, exceptionState))
         return 0;
 
@@ -193,8 +193,8 @@ DOMImplementation* DOMImplementation::getInterface(const String& /*feature*/)
     return 0;
 }
 
-PassRefPtr<Document> DOMImplementation::createDocument(const String& namespaceURI,
-    const String& qualifiedName, DocumentType* doctype, ExceptionState& exceptionState)
+PassRefPtr<Document> DOMImplementation::createDocument(const AtomicString& namespaceURI,
+    const AtomicString& qualifiedName, DocumentType* doctype, ExceptionState& exceptionState)
 {
     RefPtr<Document> doc;
     DocumentInit init = DocumentInit::fromContext(m_document.contextDocument());