This change — part of the HTML constraint-validation API (aka
“client-side form validation”) — implements the willValidate IDL/DOM
attribute/property for all form controls that support it.
This extends the optimization introduced in the previous commit to
also apply to the inserted steps for an option element. This makes
the test:
https://wpt.live/html/select/options-length-too-large.html
Go from not ever completing due to how slow it was to running, to
finishing in 800ms on my PC :^)
We can definitely expand on this a bunch more, but using the metadata
provided in the children change notification we are able to skip
runnning the expensive selectedness algorithm on the <select> element.
This removes children changed from appearing in the profile of:
https://wpt.live/html/select/options-length-too-large.html
Currently, this metadata is only provided on the insertion steps,
though I believe it would be useful to extend to the other cases
as well. This metadata can aid in making optimizations for these
steps by providing extra context into the type of change which
was made on the child.
This is still called _way_ too often, and we need to be much smarter
about when this needs to run. But we get two wins from this very
naive implementation:
1. There is a inner text setter nested within the selectedness
steps uses this list of elements. This saves us building
up a list of elements again within these steps.
2. More importantly, it caches the number of selected elements.
This already allows us to skip a minor amount of work iterating
over the children again. But in future commits, this will serve
as one of the criteria for skipping running the selectedness
algorithm altogether for certain cases, which is a very big win.
A example future idea might be to append to this list directly when
something like appendChild is run instead of iterating over all of
the children again. But that's left as future work.
This change ensures that the correct default value of 0 is used and
that values greater than 2147483647 will fall back to the default value.
It also splits the display size concept into a separate method, as
this isn't supposed to be used when getting the IDL property.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
Now that we have RTTI in userspace, we can do away with all this manual
hackery and use dynamic_cast.
We keep the is<T> and downcast<T> helpers since they still provide good
readability improvements. Note that unlike dynamic_cast<T>, downcast<T>
does not fail in a recoverable way, but will assert if the object being
casted is not a T.
