Fix TestRunnerTest to actually fail if one of the test tests has unexpected output.

tests/standalone/src/TestRunnerTest.dart

 
 // Copyright (c) 2011, 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("TestRunnerTest");
 
 
 #import("../../../tools/testing/dart/test_runner.dart");
 
 // TODO(whesse) source("ProcessTestUtil.dart"); when it is committed.
 
 class TestController {
   static final int numTests = 4;
   static int numCompletedTests = 0;
 
   // Used as TestCase.completedCallback.
   static processCompletedTest(TestCase testCase) {
     TestOutput output = testCase.output;
     print("Test: ${testCase.commandLine}");
     if (output.unexpectedOutput) {
-      print("Unexpected output: ${output.result}");
+      throw "Unexpected output: ${output.result}";
     }
     print("stdout: ");
     for (var line in output.stdout) print(line);
     print("stderr: ");
     for (var line in output.stderr) print(line);
     
     print("Time: ${output.time}");
     print("Exit code: ${output.exitCode}");
 
     ++numCompletedTests;
@@ skipping 44 matching lines @@
                                   const ["0", "0", "1", "1"],
                                   TestController.processCompletedTest,
                                   new Set<String>.from([CRASH])),
                      timeout).start();
   Expect.equals(4, TestController.numTests);
   // Throw must be from body of start() function for this test to work.
   Expect.throws(
       new RunningProcess(MakeTestCase("PassTest", [SKIP]), timeout).start);
 }