Simon Fraser

I couple of thoughts before I do a full review. 1. `perspective` can be animated; do we map this to a hardware animation now? With your patch, do we correctly...

> #### [e5da499](https://github.com/WebKit/WebKit/commit/e5da4996b595aa981503c15a5f9081e010067a4d) > Make WebGL use GPU process on macOS layout tests by default Is this just about layout tests? I think it enables it on macOS in general?

Sadly this landed with the confusing title.

You have both: `SPECIALIZE_TYPE_TRAITS_SCROLLING_NODE(ScrollingTreePositionedNode, isPositionedNode())` and `SPECIALIZE_TYPE_TRAITS_SCROLLING_NODE(ScrollingTreePositionedNodeCocoa, isPositionedNode())` which can result in type confusion. The Cocoa one needs a unique predicate. `ScrollingTreeStickyNodeCocoa` is also wrong.

The workaround is for offset() to diff the documentElement's getBoundingClientRect and the element's getBoundingClientRect if I recall correctly.

The appearance of images with no `src` also needs to be controllable. Currently UAs draw an outline which is not overridable in CSS (https://bugs.webkit.org/show_bug.cgi?id=171326); ideally that rendering would be described...

Being tracked in WebKit as https://bugs.webkit.org/show_bug.cgi?id=204013 It seems like Google worked around this by using a different animation.

I second the need for this. The name of the loaded JSON file should show in the window title, and in the content somewhere.

The title is set from the `name` value in the JSON. However, this may not be unique between JSON files, especially when comparing output from a tool, so the request...

Some initial thoughts: 1. The name of the API should be "Long tasks reporting" or "Long tasks detection" or "Long tasks performance entries". This isn't really a new API, it's...