Add WTF::String::emptyString16Bit

Source/wtf/text/StringStatics.cpp

 /*
  * Copyright (C) 2010 Apple 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 16 matching lines @@
 #include "StringStatics.h"
 
 #include "AtomicString.h"
 #include "StringImpl.h"
 #include "wtf/DynamicAnnotations.h"
 #include "wtf/MainThread.h"
 #include "wtf/StaticConstructors.h"
 
 namespace WTF {
 
-StringImpl* StringImpl::empty()
+StringImpl* StringImpl::empty(bool is8Bit)
 {
-    DEFINE_STATIC_LOCAL(StringImpl, emptyString, (ConstructEmptyString));
-    WTF_ANNOTATE_BENIGN_RACE(&emptyString, "Benign race on StringImpl::emptyString reference counter");
-    return &emptyString;
+    DEFINE_STATIC_LOCAL(StringImpl, empty8BitString, (ConstructEmpty8BitString));
+    DEFINE_STATIC_LOCAL(StringImpl, empty16BitString, (ConstructEmpty16BitString));
+    WTF_ANNOTATE_BENIGN_RACE(&empty8BitString, "Benign race on StringImpl::empty8BitString reference counter");
+    WTF_ANNOTATE_BENIGN_RACE(&empty16BitString, "Benign race on StringImpl::empty16BitString reference counter");
+    return is8Bit ? &empty8BitString : &empty16BitString;
 }
 
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, nullAtom)
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, emptyAtom)
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, starAtom)
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, xmlAtom)
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, xmlnsAtom)
 WTF_EXPORT DEFINE_GLOBAL(AtomicString, xlinkAtom)
 
 // This is not an AtomicString because it is unlikely to be used as an
@@ skipping 24 matching lines @@
 
     // FIXME: These should be allocated at compile time.
     new (NotNull, (void*)&starAtom) AtomicString("*", AtomicString::ConstructFromLiteral);
     new (NotNull, (void*)&xmlAtom) AtomicString("xml", AtomicString::ConstructFromLiteral);
     new (NotNull, (void*)&xmlnsAtom) AtomicString("xmlns", AtomicString::ConstructFromLiteral);
     new (NotNull, (void*)&xlinkAtom) AtomicString("xlink", AtomicString::ConstructFromLiteral);
     new (NotNull, (void*)&xmlnsWithColon) String("xmlns:");
 }
 
 }