Stop worrying about tiny OOMs. Work towards #20449.
While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
When toggling `display: none` on an element, it can go from having a
layout subtree to not having one. In the `none` case, we were previously
leaving stale layout nodes hanging off DOM nodes in the subtree.
These layout nodes could be queried for outdated information and
probably other things that we shouldn't allow.
Fix this by having TreeBuilder prune any old layout nodes hanging off
nodes in a subtree after its subtree root doesn't produce a layout node.
Introduce optimization that determines if one node is preceding,
following, ancestor or descdendant of another node by comparing
ancestors chains of both nodes which is much cheaper than using
Node::is_before() that can walk whole subtree in the worst case.
By deferring allocation of StaticNodeList objects until we know somebody
actually wants the MutationRecord, we avoid a *lot* of allocation work.
This shaves several seconds off of loading https://tc39.es/ecma262/
At least one other engine (WebKit) skips creating mutation records if
nobody is interested, so even if this is observable somehow, we would
at least match the behavior of a major engine.
It's not enough to invalidate only layout, since changes to the DOM tree
may also cause different selectors to apply.
This brings Acid3 back to a score of 100/100. The problem was that a
:last-child selector wasn't rechecked after removing a node that was
previously the last child of its parent.
Regression from f36cbd3b65.
The "browsing context container" concept in the HTML spec has been
replaced with "navigable container". Renaming this is the first step of
many towards implementing the new world.
Co-authored-by: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
The name "initial containing block" was wrong for this, as it doesn't
correspond to the HTML element, and that's specifically what it's
supposed to do! :^)
This is an initial implementation of the accname standard. There is
still some of the algorithm left unimplemented that we will need
to implement in the future. However, as is, this implementation is
sufficient for basic pages.
The shadowRoot property getter that will be added in subsequent commits
has an additional check that checks whether the shadow root is opened.
I didn't update the function logic to match with the IDL interface,
because it's very likely we don't want that check in the existing code,
so that for example closed shadow root elements can still be updated.
Having an alias function that only wraps another one is silly, and
keeping the more obvious name should flush out more uses of deprecated
strings.
No behavior change.
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
