Use scrollMargin for lazy load intersection observer

[johannesodland]

19ed0f7

Use scrollMargin for lazy load intersection observer
https://bugs.webkit.org/show_bug.cgi?id=264864

Reviewed by Tim Nguyen.

Update to follow step 2 (options) in "start intersection-observing a lazy loading element":
- switch from using rootMargin to using scrollMargin in the IntersectionObserverInit dictionary.
- remove document from the IntersectionObserverInit dictionary

https://html.spec.whatwg.org/#start-intersection-observing-a-lazy-loading-element

This will allow images in scroll containers to load when they are near the viewport,
in stead of when they are intersecting the viewport.

This PR does not change the lazy load scroll margin, that will stay at 100%.

* Source/WebCore/html/LazyLoadImageObserver.cpp:
(WebCore::LazyLoadImageObserver::intersectionObserver):

Canonical link: https://commits.webkit.org/293552@main

49ceac5

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	🛠 playstation
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 99b8c96)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	🛠 playstation
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[Ahmad-S792]

@johannesodland - I am syncing the-img-element, which has few lazy loading tests, just thinking if it progresses any of them. Once land, can you rebase and test it out?

Ref - #43713

[nt1m]

Is there a test that shows the behavior difference that would fail with the previous code?

[johannesodland]

Is there a test that shows the behavior difference that would fail with the previous code?

Hopefully the image-loading-lazy-in-scroller-* tests that @Ahmad-S792 is importing in #43713 will show the difference.

[Ahmad-S792]

@johannesodland - I just merged tests after green EWS, you can now rebase and see if it progresses any test case. :-)

[johannesodland]

@johannesodland - I just merged tests after green EWS, you can now rebase and see if it progresses any test case. :-)

Thanks 🙏

I've rebased locally, but it's not passing the tests the way I expected, so I'll investigate before I push an update.

[webkit-early-warning-system]

EWS run on current version of this PR (hash 49ceac5)

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	🛠 playstation
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[Ahmad-S792]

@johannesodland - Thanks! Good to see some WPT progressions. @nt1m - now it is up for your review or Simon.

[webkit-ews-buildbot]

Safe-Merge-Queue: Build #54084.

[webkit-commit-queue]

Committed 293552@main (19ed0f7): https://commits.webkit.org/293552@main

Reviewed commits have been landed. Closing PR #43712 and removing active labels.