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

third_party/WebKit/Source/core/editing/serializers/Serialization.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 243 matching lines @@
 // range.markupString()
 template <typename Strategy>
 String CreateMarkupAlgorithm<Strategy>::createMarkup(
     const PositionTemplate<Strategy>& startPosition,
     const PositionTemplate<Strategy>& endPosition,
     EAnnotateForInterchange shouldAnnotate,
     ConvertBlocksToInlines convertBlocksToInlines,
     EAbsoluteURLs shouldResolveURLs,
     Node* constrainingAncestor) {
   if (startPosition.isNull() || endPosition.isNull())
-    return emptyString();
+    return emptyString;
 
   RELEASE_ASSERT(startPosition.compareTo(endPosition) <= 0);
 
   bool collapsed = startPosition == endPosition;
   if (collapsed)
-    return emptyString();
+    return emptyString;
   Node* commonAncestor =
       Strategy::commonAncestor(*startPosition.computeContainerNode(),
                                *endPosition.computeContainerNode());
   if (!commonAncestor)
-    return emptyString();
+    return emptyString;
 
   Document* document = startPosition.document();
 
   DCHECK(!document->needsLayoutTreeUpdate());
   DocumentLifecycle::DisallowTransitionScope disallowTransition(
       document->lifecycle());
 
   HTMLElement* specialCommonAncestor = highestAncestorToWrapMarkup<Strategy>(
       startPosition, endPosition, shouldAnnotate, constrainingAncestor);
   StyledMarkupSerializer<Strategy> serializer(
@@ skipping 489 matching lines @@
   textNode->appendData(textNext->data());
   if (textNext->parentNode())  // Might have been removed by mutation event.
     textNext->remove(exceptionState);
 }
 
 template class CORE_TEMPLATE_EXPORT CreateMarkupAlgorithm<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT
     CreateMarkupAlgorithm<EditingInFlatTreeStrategy>;
 
 }  // namespace blink