Use longer animation durations in animation-display-lock.html to avoid intermittent failures on slow configurations.
Before this change, some pieces of this test intermittently timed out or failed
to run, in the more-heavyweight Firefox configurations (e.g. TSAN/ASAN,
particularly with debugging enabled). These failures seem to be because the
animation/transition durations in this test were too short, such that the
animation/transition occasionally complete on their own before the test is
ready for them to complete (i.e. before the test explicitly advances to the end
of an animation by programmatically setting 'currentTime').
I can reproduce similar failures in release Firefox and Chrome builds if I
simply reduce the animation/transition durations (from 1s to 0.1s), so I think
these failures are an indication of a race condition in the test logic (a
fragile dependency on the animation taking "long enough" that it won't complete
on its own), rather than a browser bug.
This patch attempts to avoid these intermittent failures by increasing the
animation durations by 10x, so that they're much less likely to complete on
their own. Note that the standard WPT test-timeout is 10s, so it's reasonable
to expect that the test shouldn't take longer than that (and hence we won't
accidentally let these animations play to completion before the test logic has
a chance to advance them).
This patch also updates the logic/expectations to account for the new
duration. e.g. we now set currentTime to 19999 (19.999s) rather than 1.999
(1.99s), to advance to just before the end of the second repetition of our
animation. And this means we'll be slightly further through the animation, so
the test's assertions now expect an opacity of 0.9999 rather than just 0.999.
Differential Revision: https://phabricator.services.mozilla.com/D224371
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1922353
gecko-commit: 438cafb138808a2b8f7921cd4abd89718a6c4c23
gecko-reviewers: boris