The Window object is massive, so let's do the conversion to IDL step
by step. First up: getting rid of the manual constructor and prototype
definitions, which can be generated from an empty `interface Window`.
This class had slightly confusing semantics and the added weirdness
doesn't seem worth it just so we can say "." instead of "->" when
iterating over a vector of NNRPs.
This patch replaces NonnullRefPtrVector<T> with Vector<NNRP<T>>.
This will allow us to easily share the implementations of these methods
between Window and WorkerGlobalScope. The mixin class mirrors what I
already did for the Fetch API's Body mixin in 5ad62833.
This adds the regions generated from embedded CSS and JS, and also for
HTML block comments.
The glaring omission is that we don't add them for start/end tags. HTML
allows start and end tags to not always match up, and I believe that's
going to require some variation on the adoption-agency algorithm to
make it work correctly.
Comes with the usual benefit of saving some space on the stack, as well
as making a situation where both or neither Optionals hold a value
impossible.
The various unwrapping additions are required as we can no longer
construct a ThrowCompletionOr<T> from an Optional<T> - rightfully so.
With the GC heap conversion, the functionality of legacy platform
objects was broken. This is because the generated implementation of one
of them was used for all of them, removing functionality such as
deletion.
This re-adds all functionality, where questions such as "does the
object support indexed properties?" is instead answered by virtual
functions instead of by the IDL generator checking the presence of
certain keywords/attributes.
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! :^)
Defining it as a direct property causes it to have no getter/setter
function, which causes an empty Optional crash when attempting to
access such getter on a cross-origin iframe.
Fixes amazon.com crashing on this particular crash.
