Bug 897789 - Add a fuzz factor to watchdog tests. r=Waldo

CLOSED TREE

js/xpconnect/tests/unit/test_watchdog.js

@@ -144,10 +144,16 @@ function testBody() {
   do_log_info("stateChange: " + stateChange / 1000000);
   do_log_info("startHibernation: " + startHibernation / 1000000);
   do_log_info("stopHibernation: " + stopHibernation / 1000000);
-  do_check_true(stateChange > now + 10*1000*1000);
-  do_check_true(startHibernation > now + 2*1000*1000);
-  do_check_true(startHibernation < now + 5*1000*1000);
-  do_check_true(stopHibernation > now + 10*1000*1000);
+  // XPCOM timers, JS times, and PR_Now() are apparently not directly
+  // comparable, as evidenced by certain seemingly-impossible timing values
+  // that occasionally get logged in windows automation. We're really just
+  // making sure this behavior is roughly as expected on the macro scale,
+  // so we add a 1 second fuzz factor here.
+  const FUZZ_FACTOR = 1 * 1000 * 1000;
+  do_check_true(stateChange > now + 10*1000*1000 - FUZZ_FACTOR);
+  do_check_true(startHibernation > now + 2*1000*1000 - FUZZ_FACTOR);
+  do_check_true(startHibernation < now + 5*1000*1000 + FUZZ_FACTOR);
+  do_check_true(stopHibernation > now + 10*1000*1000 - FUZZ_FACTOR);
 
   do_test_finished();
   yield;