Make HashTraits<QualifiedName>::emptyValue return a const reference

third_party/WebKit/Source/core/dom/QualifiedName.h

 /*
  * Copyright (C) 2005, 2006, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 162 matching lines @@
   // This constructor is used only to create global/static QNames that don't
   // require any ref counting.
   QualifiedName(const AtomicString& prefix,
                 const AtomicString& localName,
                 const AtomicString& namespaceURI,
                 bool isStatic);
 
   RefPtr<QualifiedNameImpl> m_impl;
 };
 
+CORE_EXPORT extern const QualifiedName& nullName;
+inline const QualifiedName& QualifiedName::null() {

[sof, 2017/03/07 12:45:33]

I'd prefer to define this 'inplace' with the static decl.

[fs, 2017/03/07 13:30:33]

Done.

+  return nullName;
+}
+
 extern const QualifiedName& anyName;
 inline const QualifiedName& anyQName() {
   return anyName;
 }
 
 inline bool operator==(const AtomicString& a, const QualifiedName& q) {
   return a == q.localName();
 }
 inline bool operator!=(const AtomicString& a, const QualifiedName& q) {
   return a != q.localName();
@@ skipping 36 matching lines @@
 
 template <>
 struct DefaultHash<blink::QualifiedName> {
   typedef blink::QualifiedNameHash Hash;
 };
 
 template <>
 struct HashTraits<blink::QualifiedName>
     : SimpleClassHashTraits<blink::QualifiedName> {
   static const bool emptyValueIsZero = false;
-  static blink::QualifiedName emptyValue() {
+  static const blink::QualifiedName& emptyValue() {
     return blink::QualifiedName::null();
   }
 };
 }  // namespace WTF
 
 #endif