Remove deprecated StringBuffer.add, addAll and addCharCode.

utils/css/uitest.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
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:html';
 import 'css.dart';
 import '../lib/file_system_memory.dart';
 
 void runCss([bool debug = false, bool parseOnly = false]) {
   final Document doc = window.document;
@@ skipping 25 matching lines @@
       templateValid = false;
       dumpTree = cssException.toString();
     }
   } else if (parseOnly) {
     try {
       Parser parser = new Parser(new SourceFile(
           SourceFile.IN_MEMORY_FILE, cssExpr));
       Stylesheet stylesheet = parser.parse();
       StringBuffer stylesheetTree = new StringBuffer();
       String prettyStylesheet = stylesheet.toString();
-      stylesheetTree.add("${prettyStylesheet}\n");
-      stylesheetTree.add("\n============>Tree Dump<============\n");
-      stylesheetTree.add(stylesheet.toDebugString());
+      stylesheetTree.write("${prettyStylesheet}\n");
+      stylesheetTree.write("\n============>Tree Dump<============\n");
+      stylesheetTree.write(stylesheet.toDebugString());
       dumpTree = stylesheetTree.toString();
     } catch (cssParseException) {
       templateValid = false;
       dumpTree = cssParseException.toString();
     }
   } else {
     try {
       dumpTree = cssParseAndValidateDebug(cssExpr, cssWorld);
     } catch (cssException) {
       templateValid = false;
@@ skipping 123 matching lines @@
     runCss();
   });
 
   ButtonElement debugButton = window.document.query('#debug');
   debugButton.on.click.add((MouseEvent e) {
     runCss(true);
   });
 
   initCssWorld(false);
 }