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

third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 104 matching lines @@
     return imgTag.localName();
   if (match(tagImpl, inputTag))
     return inputTag.localName();
   if (match(tagImpl, linkTag))
     return linkTag.localName();
   if (match(tagImpl, scriptTag))
     return scriptTag.localName();
   if (match(tagImpl, videoTag))
     return videoTag.localName();
   NOTREACHED();
-  return emptyString();
+  return emptyString;
 }
 
 static bool mediaAttributeMatches(const MediaValuesCached& mediaValues,
                                   const String& attributeValue) {
   MediaQuerySet* mediaQueries = MediaQuerySet::create(attributeValue);
   MediaQueryEvaluator mediaQueryEvaluator(mediaValues);
   return mediaQueryEvaluator.eval(mediaQueries);
 }
 
 class TokenPreloadScanner::StartTagScanner {
@@ skipping 300 matching lines @@
     String url = stripLeadingAndTrailingHTMLSpaces(value);
     if (url.isEmpty())
       return;
     m_urlToLoad = url;
   }
 
   const String& charset() const {
     // FIXME: Its not clear that this if is needed, the loader probably ignores
     // charset for image requests anyway.
     if (match(m_tagImpl, imgTag) || match(m_tagImpl, videoTag))
-      return emptyString();
+      return emptyString;
     return m_charset;
   }
 
   WTF::Optional<Resource::Type> resourceTypeForLinkPreload() const {
     DCHECK(m_linkIsPreload);
     return LinkLoader::getResourceTypeFromAsAttribute(m_asAttributeValue);
   }
 
   Resource::Type resourceType() const {
     if (match(m_tagImpl, scriptTag)) {
@@ skipping 465 matching lines @@
   defaultViewportMinWidth = document->viewportDefaultMinWidth();
   viewportMetaZeroValuesQuirk =
       document->settings() &&
       document->settings()->getViewportMetaZeroValuesQuirk();
   viewportMetaEnabled =
       document->settings() && document->settings()->getViewportMetaEnabled();
   referrerPolicy = document->getReferrerPolicy();
 }
 
 }  // namespace blink