More performance fixes.

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 362 matching lines @@
 
 
 Token::Kind Parser::LookaheadToken(int num_tokens) {
   CompilerStats::num_tokens_lookahead++;
   CompilerStats::num_token_checks++;
   return tokens_iterator_.LookaheadTokenKind(num_tokens);
 }
 
 
 String* Parser::CurrentLiteral() const {
-  String& result = String::ZoneHandle(isolate_, String::null());
-  result = tokens_iterator_.CurrentLiteral();
+  String& result =
+      String::ZoneHandle(isolate_, tokens_iterator_.CurrentLiteral());
   return &result;
 }
 
 
 RawDouble* Parser::CurrentDoubleLiteral() const {
   literal_token_ ^= tokens_iterator_.CurrentToken();
   ASSERT(literal_token_.kind() == Token::kDOUBLE);
   return Double::RawCast(literal_token_.value());
 }
 
@@ skipping 10379 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart