Replace StringImpl::empty{16Bit}() with a static member

third_party/WebKit/Source/wtf/text/AtomicStringTable.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 "wtf/text/AtomicStringTable.h"
 
 #include "wtf/text/StringHash.h"
 #include "wtf/text/UTF8.h"
 
 namespace WTF {
@@ skipping 130 matching lines @@
     location->setHash(hash);
     location->setIsAtomic(true);
   }
 };
 
 PassRefPtr<StringImpl> AtomicStringTable::add(const UChar* s, unsigned length) {
   if (!s)
     return nullptr;
 
   if (!length)
-    return StringImpl::empty();
+    return StringImpl::empty;
 
   UCharBuffer buffer = {s, length};
   return addToStringTable<UCharBuffer, UCharBufferTranslator>(buffer);
 }
 
 typedef HashTranslatorCharBuffer<LChar> LCharBuffer;
 struct LCharBufferTranslator {
   static unsigned hash(const LCharBuffer& buf) {
     return StringHasher::computeHashAndMaskTop8Bits(buf.s, buf.length);
   }
 
   static bool equal(StringImpl* const& str, const LCharBuffer& buf) {
     return WTF::equal(str, buf.s, buf.length);
   }
 
   static void translate(StringImpl*& location,
                         const LCharBuffer& buf,
                         unsigned hash) {
     location = StringImpl::create(buf.s, buf.length).leakRef();
     location->setHash(hash);
     location->setIsAtomic(true);
   }
 };
 
 PassRefPtr<StringImpl> AtomicStringTable::add(const LChar* s, unsigned length) {
   if (!s)
     return nullptr;
 
   if (!length)
-    return StringImpl::empty();
+    return StringImpl::empty;
 
   LCharBuffer buffer = {s, length};
   return addToStringTable<LCharBuffer, LCharBufferTranslator>(buffer);
 }
 
 StringImpl* AtomicStringTable::add(StringImpl* string) {
   if (!string->length())
-    return StringImpl::empty();
+    return StringImpl::empty;
 
   StringImpl* result = *m_table.insert(string).storedValue;
 
   if (!result->isAtomic())
     result->setIsAtomic(true);
 
   DCHECK(!string->isStatic() || result->isStatic());
   return result;
 }
 
@@ skipping 12 matching lines @@
 }
 
 void AtomicStringTable::remove(StringImpl* string) {
   DCHECK(string->isAtomic());
   auto iterator = m_table.find(string);
   RELEASE_ASSERT(iterator != m_table.end());
   m_table.remove(iterator);
 }
 
 }  // namespace WTF