rIC: change deadline-after-expired-timer.html asserts

This CL changes the test expectation that the deadline is positive when
an idle callback runs after a timer expires to non-negative (which
matches the test title). On slow or overloaded machines, it's possible
for the deadline to be reached while running the callback, in which
case the deadline.timeRemaining() will be 0 and the test will fail.
Per spec, the timeRemaining() must never be < 0, but 0 is valid in this
test, so this changes the assertion to greater_than_equal.

Bug: 1329281
Change-Id: Ie0d42e7fd0b47579edc72ae5a7889e2e8475b266
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4622374
Commit-Queue: Scott Haseley <shaseley@chromium.org>
Reviewed-by: Noam Rosenthal <nrosenthal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1160116}
diff --git a/requestidlecallback/deadline-after-expired-timer.html b/requestidlecallback/deadline-after-expired-timer.html
index 47396ea..b544141 100644
--- a/requestidlecallback/deadline-after-expired-timer.html
+++ b/requestidlecallback/deadline-after-expired-timer.html
@@ -11,7 +11,7 @@
       requestIdleCallback(
         t.step_func((deadline) => {
           assert_false(deadline.didTimeout);
-          assert_greater_than(deadline.timeRemaining(), 0);
+          assert_greater_than_equal(deadline.timeRemaining(), 0);
           t.done();
         }),
         { timeout: 1000 }