Add back three deprecated DOM APIs removed from Chrome 34

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 8c770732ac76657342f57532da35367f200f9e9a..43e7d00eda7ca34bfb28f3657c8b644e2c9260bd 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -4427,11 +4427,21 @@ WeakPtr<Document> Document::contextDocument()
 
 PassRefPtr<Attr> Document::createAttribute(const AtomicString& name, ExceptionState& exceptionState)
 {
+    return createAttributeNS(nullAtom, name, exceptionState, true);
+}
+
+PassRefPtr<Attr> Document::createAttributeNS(const AtomicString& namespaceURI, const AtomicString& qualifiedName, ExceptionState& exceptionState, bool shouldIgnoreNamespaceChecks)
+{
     AtomicString prefix, localName;
-    if (!parseQualifiedName(name, prefix, localName, exceptionState))
+    if (!parseQualifiedName(qualifiedName, prefix, localName, exceptionState))
         return nullptr;
 
-    QualifiedName qName(prefix, localName, nullAtom);
+    QualifiedName qName(prefix, localName, namespaceURI);
+
+    if (!shouldIgnoreNamespaceChecks && !hasValidNamespaceForAttributes(qName)) {
+        exceptionState.throwDOMException(NamespaceError, "The namespace URI provided ('" + namespaceURI + "') is not valid for the qualified name provided ('" + qualifiedName + "').");
+        return nullptr;
+    }
 
     return Attr::create(*this, qName, emptyAtom);
 }