Bug 662178 - Harden test_utils_namedTimer.js. r=rnewman

services/sync/tests/unit/test_utils_namedTimer.js

@@ -28,7 +28,9 @@ add_test(function test_simple() {
     do_check_eq(this, that);
     do_check_eq(this._zetimer, null);
     do_check_true(timer instanceof Ci.nsITimer);
-    do_check_true((Date.now() - t0) >= delay);
+    // Difference should be ~delay, but hard to predict on all platforms,
+    // particularly Windows XP.
+    do_check_true(Date.now() > t0);
     run_next_test();
   }, delay, that, "_zetimer");
 });
@@ -40,8 +42,9 @@ add_test(function test_delay() {
   let that = {};
   let t0 = Date.now();
   function callback(timer) {
-    // The 2nd delay counts.
-    do_check_true((Date.now() - t0) >= 2 * delay);
+    // Difference should be ~2*delay, but hard to predict on all platforms,
+    // particularly Windows XP.
+    do_check_true((Date.now() - t0) > delay);
     run_next_test();
   }
   Utils.namedTimer(callback, delay, that, "_zetimer");