Replace WTF::emptyString{16Bit}() with a static global

third_party/WebKit/Source/core/html/HTMLFormControlElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * 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
@@ skipping 66 matching lines @@
   return document().completeURL(stripLeadingAndTrailingHTMLSpaces(action));
 }
 
 void HTMLFormControlElement::setFormAction(const AtomicString& value) {
   setAttribute(formactionAttr, value);
 }
 
 String HTMLFormControlElement::formEnctype() const {
   const AtomicString& formEnctypeAttr = fastGetAttribute(formenctypeAttr);
   if (formEnctypeAttr.isNull())
-    return emptyString();
+    return emptyString;
   return FormSubmission::Attributes::parseEncodingType(formEnctypeAttr);
 }
 
 void HTMLFormControlElement::setFormEnctype(const AtomicString& value) {
   setAttribute(formenctypeAttr, value);
 }
 
 String HTMLFormControlElement::formMethod() const {
   const AtomicString& formMethodAttr = fastGetAttribute(formmethodAttr);
   if (formMethodAttr.isNull())
-    return emptyString();
+    return emptyString;
   return FormSubmission::Attributes::methodString(
       FormSubmission::Attributes::parseMethodType(formMethodAttr));
 }
 
 void HTMLFormControlElement::setFormMethod(const AtomicString& value) {
   setAttribute(formmethodAttr, value);
 }
 
 bool HTMLFormControlElement::formNoValidate() const {
   return fastHasAttribute(formnovalidateAttr);
@@ skipping 525 matching lines @@
     const Element& source) {
   HTMLElement::copyNonAttributePropertiesFromElement(source);
   setNeedsValidityCheck();
 }
 
 void HTMLFormControlElement::associateWith(HTMLFormElement* form) {
   associateByParser(form);
 };
 
 }  // namespace blink