Introduce VirtualMethods::children_changed()
This virtual method mimics the behaviour of mutation observers and make it more viable than the older child_inserted(), which didn't cover removed nodes and was called as many times as there were inserted nodes.
A few other shortcomings where remove_child() was called directly instead of Node::remove() were also fixed while at it.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/6660)
<!-- Reviewable:end -->
Refactor #[jstraceable] to #[derive(JSTraceable)]
fixes#6524. I had to make an additional change not mentioned in the ticket - adding the `#[feature]` to enable deriving custom traits but I assume that's expected at this time.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/6529)
<!-- Reviewable:end -->
The util component specified fnv and smallvec as dependencies and publicly
reexported both of them. Several other components utilized these reexports,
presumably because fnv and smallvec used to live in the tree so reexporting
made the transition easier.
These indirect dependencies through the util component are unnecessary.
This commit removes the fnv & smallvec crate reexports in the util component.
It exchange, it adds fnv & smallvec as dependencies to non-util components
wherever needed. Finally, it removes the fnv dependency from util as it is not
utilized anywhere in the util component.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/6317)
<!-- Reviewable:end -->
The util component specified fnv and smallvec as dependencies and publicly
reexported both of them. Several other components utilized these reexports,
presumably because fnv and smallvec used to live in the tree so reexporting
made the transition easier.
These indirect dependencies through the util component are unnecessary.
This commit removes the fnv & smallvec crate reexports in the util component.
It exchange, it adds fnv & smallvec as dependencies to non-util components
wherever needed. Finally, it removes the fnv dependency from util as it is not
utilized anywhere in the util component.
Added support for the tabindex field, also added its correct defaults (-2 TODOs for things not supported in Servo yet). Also added tabindex logic into Element::is_focusable_area.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/5858)
<!-- Reviewable:end -->