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

third_party/WebKit/Source/core/css/CSSSyntaxDescriptor.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/CSSSyntaxDescriptor.h"
 
 #include "core/animation/CSSColorInterpolationType.h"
 #include "core/animation/CSSValueInterpolationType.h"
 #include "core/css/CSSCustomPropertyDeclaration.h"
 #include "core/css/CSSURIValue.h"
@@ skipping 81 matching lines @@
 }
 
 CSSSyntaxDescriptor::CSSSyntaxDescriptor(String input) {
   size_t offset = 0;
   consumeWhitespace(input, offset);
 
   if (consumeCharacterAndWhitespace(input, '*', offset)) {
     if (offset != input.length())
       return;
     m_syntaxComponents.push_back(
-        CSSSyntaxComponent(CSSSyntaxType::TokenStream, emptyString(), false));
+        CSSSyntaxComponent(CSSSyntaxType::TokenStream, emptyString, false));
     return;
   }
 
   do {
     CSSSyntaxType type;
     String ident;
     bool success;
 
     if (input[offset] == '<') {
       success = consumeSyntaxType(input, offset, type);
@@ skipping 137 matching lines @@
         NOTREACHED();
         break;
     }
   }
   interpolationTypes.push_back(
       WTF::makeUnique<CSSValueInterpolationType>(property));
   return interpolationTypes;
 }
 
 }  // namespace blink