 tr.b.forcePendingRAFTasksToRun(fakeNow);
      assert.isTrue(idle1Ran);
      assert.isFalse(idle2Ran);

      // Reset idle1Ran to verify that it dosn't run again.
      idle1Ran = false;

      // Now run. idle2 should now run.
      tr.b.forcePendingRAFTasksToRun(fakeNow);
      assert.isFalse(idle1Ran);
      assert.isTrue(idle2Ran);
    });
  });

  test('buggyPerformanceNowDoesNotBlockIdleTasks', function() {
    withMockedScheduling(function() {
      tr.b.forcePendingRAFTasksToRun();  // Clear curr