Remove deprecated StringBuffer.add, addAll and addCharCode.

pkg/scheduled_test/test/metatest.dart

 // Copyright (c) 2013, 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.
 
 /// A test library for testing test libraries? We must go deeper.
 ///
 /// Since unit testing code tends to use a lot of global state, it can be tough
 /// to test. This library manages it by running each test case in a child
 /// isolate, then reporting the results back to the parent isolate.
 library metatest;
@@ skipping 119 matching lines @@
 /// an error occurred.
 bool _hasError(Map results) {
   return results['errors'] > 0 || results['uncaughtError'] != null ||
     (results['passed'] == 0 && results['failed'] == 0);
 }
 
 /// Returns a string description of the test run descibed by [results].
 String _summarizeTests(Map results) {
   var buffer = new StringBuffer();
   for (var t in results["results"]) {
-    buffer.add("${t['result'].toUpperCase()}: ${t['description']}\n");
-    if (t['message'] != '') buffer.add("${_indent(t['message'])}\n");
+    buffer.writeln("${t['result'].toUpperCase()}: ${t['description']}");
+    if (t['message'] != '') buffer.writeln("${_indent(t['message'])}");
     if (t['stackTrace'] != null && t['stackTrace'] != '') {
-      buffer.add("${_indent(t['stackTrace'])}\n");
+      buffer.writeln("${_indent(t['stackTrace'])}");
     }
   }
 
-  buffer.add("\n");
+  buffer.writeln("");
 
   var success = false;
   if (results['passed'] == 0 && results['failed'] == 0 &&
       results['errors'] == 0 && results['uncaughtError'] == null) {
-    buffer.add('No tests found.');
+    buffer.write('No tests found.');
     // This is considered a failure too.
   } else if (results['failed'] == 0 && results['errors'] == 0 &&
       results['uncaughtError'] == null) {
-    buffer.add('All ${results['passed']} tests passed.');
+    buffer.write('All ${results['passed']} tests passed.');
     success = true;
   } else {
     if (results['uncaughtError'] != null) {
-      buffer.add('Top-level uncaught error: ${results['uncaughtError']}');
+      buffer.write('Top-level uncaught error: ${results['uncaughtError']}');
     }
-    buffer.add('${results['passed']} PASSED, ${results['failed']} FAILED, '
+    buffer.write('${results['passed']} PASSED, ${results['failed']} FAILED, '
         '${results['errors']} ERRORS');
   }
   return prefixLines(buffer.toString());
 }
 
 /// Indents each line of [str] by two spaces.
 String _indent(String str) {
   // TODO(nweiz): Use this simpler code once issue 2980 is fixed.
   // return str.replaceAll(new RegExp("^", multiLine: true), "  ");
 
@@ skipping 24 matching lines @@
         "message": testCase.message,
         "result": testCase.result,
         "stackTrace": testCase.stackTrace
       }).toList()
     });
   }
 
   void onInit() {}
   void onDone(bool success) {}
 }