Fix comment.

pkg/scheduled_test/lib/scheduled_process.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.
 
 library scheduled_test.scheduled_process;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'scheduled_test.dart';
 import 'src/utils.dart';
 import 'src/value_future.dart';
 
 /// A class representing a [Process] that is scheduled to run in the course of
 /// the test. This class allows actions on the process to be scheduled
 /// synchronously. All operations on this class are scheduled.
 ///
 /// Before running the test, either [shouldExit] or [kill] must be called on
 /// this to ensure that the process terminates when expected. Note that [kill]
 /// is using SIGKILL, to ensure the process is killed on Mac OS X (an early
-/// SIGTERM on Mac OS X may be ignore).
+/// SIGTERM on Mac OS X may be ignored).
 ///
 /// If the test fails, this will automatically print out any stdout and stderr
 /// from the process to aid debugging.
 class ScheduledProcess {
   /// A description of the process. Used for error reporting.
   String get description => _description;
   String _description;
 
   /// Whether a description was passed explicitly by the user.
   bool _explicitDescription;
@@ skipping 315 matching lines @@
     schedule(() {
       _endExpected = true;
       return _exitCode.then((exitCode) {
         if (expectedExitCode != null) {
           expect(exitCode, equals(expectedExitCode));
         }
       });
     }, "waiting for process '$description' to exit");
   }
 }