Small clean up of externalizing strings.

src/factory.cc

 // Copyright 2014 the V8 project 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 "src/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/conversions.h"
 #include "src/isolate-inl.h"
 #include "src/macro-assembler.h"
@@ skipping 252 matching lines @@
   decoder->WriteUtf16(data, utf16_length);
   return result;
 }
 
 
 MaybeHandle<String> Factory::NewStringFromTwoByte(Vector<const uc16> string,
                                                   PretenureFlag pretenure) {
   int length = string.length();
   const uc16* start = string.start();
   if (String::IsOneByte(start, length)) {
+    if (length == 1) return LookupSingleCharacterStringFromCode(string[0]);
     Handle<SeqOneByteString> result;
     ASSIGN_RETURN_ON_EXCEPTION(
         isolate(),
         result,
         NewRawOneByteString(length, pretenure),
         String);
     CopyChars(result->GetChars(), start, length);
     return result;
   } else {
     Handle<SeqTwoByteString> result;
@@ skipping 2082 matching lines @@
   return Handle<Object>::null();
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 } }  // namespace v8::internal