Remove the Element.prefix setter

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1146 matching lines @@
     if (other->elementData())
         return other->elementData()->isEquivalent(elementData());
     return true;
 }
 
 String Element::nodeName() const
 {
     return m_tagName.toString();
 }
 
-void Element::setPrefix(const AtomicString& prefix, ExceptionState& exceptionState)
-{
-    UseCounter::countDeprecation(document(), UseCounter::ElementSetPrefix);
-
-    if (!prefix.isEmpty() && !Document::isValidName(prefix)) {
-        exceptionState.throwDOMException(InvalidCharacterError, "The prefix '" + prefix + "' is not a valid name.");
-        return;
-    }
-
-    // FIXME: Raise NamespaceError if prefix is malformed per the Namespaces in XML specification.
-
-    const AtomicString& nodeNamespaceURI = namespaceURI();
-    if (nodeNamespaceURI.isEmpty() && !prefix.isEmpty()) {
-        exceptionState.throwDOMException(NamespaceError, "No namespace is set, so a namespace prefix may not be set.");
-        return;
-    }
-
-    if (prefix == xmlAtom && nodeNamespaceURI != XMLNames::xmlNamespaceURI) {
-        exceptionState.throwDOMException(NamespaceError, "The prefix '" + xmlAtom + "' may not be set on namespace '" + nodeNamespaceURI + "'.");
-        return;
-    }
-
-    if (exceptionState.hadException())
-        return;
-
-    m_tagName.setPrefix(prefix.isEmpty() ? AtomicString() : prefix);
-}
-
 const AtomicString& Element::locateNamespacePrefix(const AtomicString& namespaceToLocate) const
 {
     if (!prefix().isNull() && namespaceURI() == namespaceToLocate)
         return prefix();
 
     AttributeCollection attributes = this->attributes();
     for (const Attribute& attr : attributes) {
         if (attr.prefix() == xmlnsAtom && attr.value() == namespaceToLocate)
             return attr.localName();
     }
@@ skipping 2065 matching lines @@
         return wrapper;
 
     CustomElementBinding* binding = perContextData->customElementBinding(customElementDefinition());
 
     wrapper->SetPrototype(binding->prototype());
 
     return V8DOMWrapper::associateObjectWithWrapper(isolate, this, wrapperType, wrapper);
 }
 
 } // namespace blink