Remove deprecated StringBuffer.add, addAll and addCharCode.

utils/css/parser.dart

 // 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
 
 /**
  * A simple recursive descent parser for CSS.
  */
 class Parser {
   Tokenizer tokenizer;
 
   var _fs;                        // If non-null filesystem to read files.
@@ skipping 906 matching lines @@
         _error('unexpected string', _makeSpan(start));
       }
     }
 
     StringBuffer stringValue = new StringBuffer();
 
     // Gobble up everything until we hit our stop token.
     int runningStart = _peekToken.start;
     while (_peek() != stopToken && _peek() != TokenKind.END_OF_FILE) {
       var tok = _next();
-      stringValue.add(tok.text);
+      stringValue.write(tok.text);
     }
 
     if (stopToken != TokenKind.RPAREN) {
       _next();    // Skip the SINGLE_QUOTE or DOUBLE_QUOTE;
     }
 
     return stringValue.toString();
   }
 
   //  Function grammar:
@@ skipping 70 matching lines @@
 
     return result;
   }
 }
 
 /** Not a hex number. */
 class HexNumberException implements Exception {
   HexNumberException();
 }