In `::spin_processing_tasks_with_source_until()`, we would first take a
set of tasks based on a filter, and then run them one by one. If there
was more than one task matched and put in that vector, they could
interfere with each other's runnability by making later tasks
permanently unrunnable.
The `::take_tasks_matching()` API is a footgun - remove it in favor of
an API that takes tasks one by one, performing the runnability check
just in time.
In TaskQueue::take_tasks_matching(), we were not discarding tasks for
destroyed documents as we now do in ::take_first_runnable() since commit
c8baa6e179.
This fixes some occurrences of missing browsing contexts / active
documents in TraversableNavigable::destroy_top_level_traversable().
Previously, destroyed-document tasks were forced to be runnable to
prevent them from leaking in the task queue. Instead, discard them
during task selection so their callbacks never run with stale state.
This used to cause issues with a couple of `spin_until()`s in the past,
but since we've removed some of them that had to do with the document
lifecycle, let's see if we can stick closer to the spec now.
Documents that have never been associated with a browsing context will
never become "fully active" so we shouldn't schedule tasks in them since
they'll never run.
The inert temporary documents used for fragment parsing will never
become "fully active" and so any tasks associated with them will never
run. To avoid memory leaks, we now simply ignore any attempts to enqueue
tasks associated with such documents.
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
