tree 7ab6f2f00aaba73272444f56ce91abbd240e8fe7
parent 531bf4a9a5fd6e7812a40a8df1a6c32b4ba748e3
author Stefan Zager <szager@chromium.org> 1533780874 -0700
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> 1533781397 -0400

[IntersectionObserver] Fix initial notifications for non-zero threshold

When a target is first observed, last_threshold_index_ is set to a
sentinel value (0x1fffffff), to ensure that an initial notification
will be sent on the next frame. For that notification, if the target
is intersecting, but the intersection ratio is less than the smallest
threshold set on the observer, then the isIntersecting field of the
notification should be false.

Also, for IOv2, the isVisible field should always be false -- and
skip the expensive hit test -- if the intersection ratio is less
than the smallest threshold set on the observer.

BUG=847623,827639
R=chrishtr@chromium.org

Change-Id: I518ff97a23afd92a82c4d01d9280d57ffb0c9ae2
Reviewed-on: https://chromium-review.googlesource.com/1167884
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581755}