Remove deprecated StringBuffer.add, addAll and addCharCode.

tests/standalone/io/directory_test.dart

 // 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.
 //
 // Directory listing test.
 
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
 
@@ skipping 106 matching lines @@
               });
             }
           });
       }
       var subDirName = 'subdir';
       var subDir = new Directory("${d.path}/$subDirName");
       subDir.create().then((ignore) {
         // Construct a long string of the form
         // 'tempdir/subdir/../subdir/../subdir'.
         var buffer = new StringBuffer();
-        buffer.add(subDir.path);
+        buffer.write(subDir.path);
         for (var i = 0; i < 1000; i++) {
-          buffer.add("/../${subDirName}");
+          buffer.write("/../${subDirName}");
         }
         var long = new Directory("${buffer.toString()}");
         setupListHandlers(long.list());
         setupListHandlers(long.list(recursive: true));
       });
     });
   }
 
   static void testDeleteNonExistent() {
     // Test that deleting a non-existing directory fails.
@@ skipping 15 matching lines @@
 
   static void testDeleteTooLongName() {
     var port = new ReceivePort();
     new Directory("").createTemp().then((d) {
       var subDirName = 'subdir';
       var subDir = new Directory("${d.path}/$subDirName");
       subDir.create().then((ignore) {
           // Construct a long string of the form
           // 'tempdir/subdir/../subdir/../subdir'.
           var buffer = new StringBuffer();
-          buffer.add(subDir.path);
+          buffer.write(subDir.path);
           for (var i = 0; i < 1000; i++) {
-            buffer.add("/../${subDirName}");
+            buffer.write("/../${subDirName}");
           }
           var long = new Directory("${buffer.toString()}");
           var errors = 0;
           onError(e) {
             Expect.isTrue(e.error is DirectoryIOException);
             if (++errors == 2) {
               d.delete(recursive: true).then((ignore) => port.close());
             }
             return true;
           }
@@ skipping 11 matching lines @@
   }
 
   static void testDeleteTooLongNameSync() {
     Directory d = new Directory("").createTempSync();
     var subDirName = 'subdir';
     var subDir = new Directory("${d.path}/$subDirName");
     subDir.createSync();
     // Construct a long string of the form
     // 'tempdir/subdir/../subdir/../subdir'.
     var buffer = new StringBuffer();
-    buffer.add(subDir.path);
+    buffer.write(subDir.path);
     for (var i = 0; i < 1000; i++) {
-      buffer.add("/../${subDirName}");
+      buffer.write("/../${subDirName}");
     }
     var long = new Directory("${buffer.toString()}");
     Expect.throws(long.deleteSync);
     Expect.throws(() => long.deleteSync(recursive: true));
     d.deleteSync(recursive: true);
   }
 
   static void testExistsCreateDelete() {
     new Directory("").createTemp().then((d) {
       d.exists().then((bool exists) {
@@ skipping 307 matching lines @@
   testCreateTempErrorSync();
   testCreateTempError();
   testCreateExistingSync();
   testCreateExisting();
   testCreateDirExistingFileSync();
   testCreateDirExistingFile();
   testCreateRecursive();
   testCreateRecursiveSync();
   testRename();
 }