Enable ResizeObserver by default #39790
Description
Spec: https://drafts.csswg.org/resize-observer/#resize-observer-interface
Known issues:
- Pass WPT tests for ResizeObserver #31182
- Fix DOMRect calc in ResizeObserverEntry #32549
- ResizeObserver does not properly populate ResizeObserverEntry #38811
- ResizeObserver.contentRect needs to adjust for non-SVG elements #40107
- Content box query includes non-content box sizes #40110
- ResizeObserver depth calculation isn't correct #40111
- ResizeObserver content rect calculation must not include CSS transforms #40258
- ResizeObserver content rect calculation must not work on non-replaced inline elements #40259
- Intermittent TIMEOUT in
/resize-observer/eventloop.html#33599