Changes to shrink the token stream representation from two words to one word.

vm/scanner.h

 // Copyright (c) 2011, 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.
 //
 // Scanner class for the Dart language. The scanner reads source text
 // and produces a stream of tokens which is used by the parser.
 //
 
 #ifndef VM_SCANNER_H_
 #define VM_SCANNER_H_
@@ skipping 84 matching lines @@
     ScanContext* next;
     char string_delimiter;
     bool string_is_multiline;
     int  brace_level;
   };
 
   struct KeywordTable {
     Token::Kind kind;
     const char* keyword_chars;
     int keyword_len;
-    String* keyword_symbol;
   };
 
   // Rewind scanner position to token 0.
   void Reset();
 
   // Initialize Scanner tables.
   void InitKeywordTable();
 
   // Reads next lookahead character.
   void ReadChar();
@@ skipping 93 matching lines @@
   const String& private_key_;
 
   SourcePosition c0_pos_;      // Source position of lookahead character c0_.
   KeywordTable keywords_[Token::numKeywords];
 };
 
 
 }  // namespace dart
 
 #endif  // VM_SCANNER_H_