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

third_party/WebKit/Source/core/frame/SubresourceIntegrity.cpp

 // Copyright 2014 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/frame/SubresourceIntegrity.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ExecutionContext.h"
@@ skipping 284 matching lines @@
 // [algorithm]-[hash]      OR     [algorithm]-[hash]?[options]
 //                   ^                              ^         ^
 //        position/end                       position       end
 bool SubresourceIntegrity::parseDigest(const UChar*& position,
                                        const UChar* end,
                                        String& digest) {
   const UChar* begin = position;
   skipWhile<UChar, isIntegrityCharacter>(position, end);
 
   if (position == begin || (position != end && *position != '?')) {
-    digest = emptyString();
+    digest = emptyString;
     return false;
   }
 
   // We accept base64url encoding, but normalize to "normal" base64 internally:
   digest = normalizeToBase64(String(begin, position - begin));
   return true;
 }
 
 SubresourceIntegrity::IntegrityParseResult
 SubresourceIntegrity::parseIntegrityAttribute(
@@ skipping 102 matching lines @@
     metadataSet.insert(integrityMetadata.toPair());
   }
 
   if (metadataSet.size() == 0 && error)
     return IntegrityParseNoValidResult;
 
   return IntegrityParseValidResult;
 }
 
 }  // namespace blink