This change also removes as much direct use of JS::Promise in LibWeb
as possible. When specs refer to `Promise<T>` they should be assumed
to be referring to the WebIDL Promise type, not the JS::Promise type.
The one exception is the HostPromiseRejectionTracker hook on the JS
VM. This facility and its associated sets and events are intended to
expose the exact opaque object handles that were rejected to author
code. This is not possible with the WebIDL Promise type, so we have
to use JS::Promise or JS::Object to hold onto the promises.
It also exposes which specs need some updates in the area of
promises. WebDriver stands out in this regard. WebAudio could use
some more cross-references to WebIDL as well to clarify things.
This aligns with an update to the HTML specification which instead
stores these promises on the global object instead of the settings
object.
It also makes progress towards implementing the ShadowRealm proposal
as these promises are not present in the 'synthetic' realm for that
proposal.
We now use the "report an exception" AO when a script has an execution
error. This has mostly replaced the older "report the exception" AO in
various specifications. Using this newer AO ensures that
`window.onerror` is invoked when a script has an execution error.
EventSource allows opening a persistent HTTP connection to a server over
which events are continuously streamed.
Unfortunately, our test infrastructure does not allow for automating any
tests of this feature yet. It only works with HTTP connections.
This change implements a step from the document's destroy procedure in
the specification, saying that all active timers should be cleared.
By doing this, we also fix the leaking of a document in case where we
have navigated away from a page that has scheduled timers that haven't
yet been triggered.
This is where it belongs according to the spec, and where these methods'
IDL will be placed.
This forces us to implement a few steps closer to the spec as well.
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.
