Add "point of interest" app for command-line testing of dart2js type information.

dart/tests/try/web/cursor_position_test.dart

 // Copyright (c) 2014, 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.
 
 // Test that cursor positions are correctly updated after adding new content.
 
 import 'test_try.dart';
 
 void main() {
   InteractionManager interaction = mockTryDartInteraction();
@@ skipping 94 matching lines @@
 
 class MockKeyboardEvent extends KeyEvent {
   final int keyCode;
 
   MockKeyboardEvent(String type, {int keyCode})
       : this.keyCode = keyCode,
         super.wrap(new KeyEvent(type, keyCode: keyCode));
 
   bool getModifierState(String keyArgument) => false;
 }