Dynamically load packages for dartdevc tests in test.dart.

tools/testing/dart/command_output.dart

 // Copyright (c) 2017, 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:convert';
 // We need to use the 'io' prefix here, otherwise io.exitCode will shadow
 // CommandOutput.exitCode in subclasses of CommandOutput.
 import 'dart:io' as io;
 
 import 'browser_controller.dart';
@@ skipping 66 matching lines @@
   bool get canRunDependendCommands {
     // FIXME(kustermann): We may need to change this
     return !hasTimedOut && exitCode == 0;
   }
 
   bool get successful {
     // FIXME(kustermann): We may need to change this
     return !hasTimedOut && exitCode == 0;
   }
 
-  // TODO(bob): Remove.
   // Reverse result of a negative test.
   bool hasFailed(TestCase testCase) {
     return testCase.isNegative ? !_didFail(testCase) : _didFail(testCase);
   }
 
   bool get hasNonUtf8 => exitCode == nonUtfFakeExitCode;
 
   Expectation _negateOutcomeIfNegativeTest(
       Expectation outcome, bool isNegative) {
     if (!isNegative) return outcome;
@@ skipping 732 matching lines @@
     // complete successfully, it's outcome is Expectation.FAIL.
     // TODO: maybe we should introduce a AsyncIncomplete marker or so
     if (outcome == Expectation.pass) {
       if (_isAsyncTest(testOutput) && !_isAsyncTestSuccessful(testOutput)) {
         return Expectation.fail;
       }
     }
     return outcome;
   }
 }