If we made progress, add testCases to the front of the queue in test_runner.dart

tools/testing/dart/test_runner.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 1647 matching lines @@
         runNextCommandWithRetries(test, allowRetry).then((TestCase testCase) {
           _numProcesses--;
           if (isBrowserCommand) {
             _numBrowserProcesses--;
           }
           if (isTestCaseFinished(testCase)) {
             testCase.completed();
             _progress.done(testCase);
             if (testCase is BrowserTestCase) testCase.notifyObservers();
           } else {
-            _tests.add(testCase);
+            _tests.addFirst(testCase);

[ngeoffray, 2013/01/31 12:56:31]

I thought you could not do this because if it's an IE command, and IE is taken,
you would wait for it.

[kustermann, 2013/01/31 13:01:17]

Well, I was kind of stupid. It's save to put it into the front of the queue if
we actually made some progress (for example if we did run a compilation
command). But if we dequeue it from the front and there is no slot available we
HAVE to put it on the end. (which is on line 1620).

           }
           _tryRunTest();
         });
       }
 
       _numProcesses++;
       if (isBrowserCommand) {
         _numBrowserProcesses++;
       }
     }
@@ skipping 70 matching lines @@
           completer.complete(testCase);
         }
       });
     }
     runCommand();
 
     return completer.future;
   }
 }