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

third_party/WebKit/Source/core/html/HTMLInputElement.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, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved.
@@ skipping 1005 matching lines @@
     case ValueMode::kDefault:
       return fastGetAttribute(valueAttr);
     case ValueMode::kDefaultOn: {
       AtomicString valueString = fastGetAttribute(valueAttr);
       return valueString.isNull() ? "on" : valueString;
     }
     case ValueMode::kValue:
       return m_nonAttributeValue;
   }
   NOTREACHED();
-  return emptyString();
+  return emptyString;
 }
 
 String HTMLInputElement::valueOrDefaultLabel() const {
   String value = this->value();
   if (!value.isNull())
     return value;
   return m_inputType->defaultLabel();
 }
 
 void HTMLInputElement::setValueForUser(const String& value) {
@@ skipping 849 matching lines @@
 
 bool HTMLInputElement::hasFallbackContent() const {
   return m_inputTypeView->hasFallbackContent();
 }
 
 void HTMLInputElement::setFilesFromPaths(const Vector<String>& paths) {
   return m_inputType->setFilesFromPaths(paths);
 }
 
 }  // namespace blink