Revert revision 24444, pkg/unittest/test/unittest_test is still flaky timing out on firefox

pkg/pkg.status

 # 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.
 
 # Run this test manually to verify that the fixnum library produces
 # the same results as native ints on a set of directed and random inputs.
 # Skip it when running automated tests because it times out.  This
 # test only makes sense on runtimes that support 64-bit integer
 # arithmetic natively, i.e., the VM.
 fixnum/test/int_64_vm_test: Skip
 
 # Don't run any test-like files that show up in packages directories. It
 # shouldn't be necessary to run "pub install" in these packages, but if you do
 # it shouldn't break the tests.
 */packages/*/*: Skip
 */*/packages/*/*: Skip
 */*/*/packages/*/*: Skip
 
 # Skip non-test files ending with "_test".
 scheduled_test/lib/*: Skip
 
 scheduled_test/test/scheduled_server_test: Pass, Fail, Slow, Crash # Issue 9231, 9582
 scheduled_test/test/scheduled_process_test: Pass, Slow # Issue 9231
 
 # WebDriver tests have 3rd party dependencies (we need to run
 # selenium_standalone.jar), so we skip these in our automated
 # testing.
 webdriver/test/webdriver_test: Skip
 
+[ $compiler == dart2js && $runtime == ff ]
+unittest/test/unittest_test: Pass, Timeout # http://dartbug.com/11473
+
 [ $runtime == d8 || $runtime == jsshell ]
 unittest/test/unittest_test: Pass, Fail # http://dartbug.com/10109
 
 [$compiler == dart2dart]
 *: Skip
 
 [ $compiler == dart2js || $compiler == dart2dart ]
 source_maps/test/vlq_test: Fail # A VLQ test checks for large numbers that
                                 # overflow in JS (numbers slightly larger than
                                 # 32 bits where we do bitwise operations).
@@ skipping 147 matching lines @@
 # test on Dartium, which requires all tests to have a library.
 [ $runtime == dartium || $runtime == drt ]
 serialization/test/no_library_test: Skip # Expected Failure
 
 [ ($runtime == dartium || $runtime == drt) && $compiler == none ]
 pathos/test/pathos_dart2js_test: Fail, OK # Issue 6490
 
 # Skip mdv_observe tests on command line VM, they only run in the browser.
 [ $runtime == vm ]
 mdv_observe: Skip