With this change, we now have ~1200 CellAllocators across both LibJS and
LibWeb in a normal WebContent instance.
This gives us a minimum heap size of 4.7 MiB in the scenario where we
only have one cell allocated per type. Of course, in practice there will
be many more of each type, so the effective overhead is quite a bit
smaller than that in practice.
I left a few types unconverted to this mechanism because I got tired of
doing this. :^)
Before the completion_steps for timer were casted from JS::SafeFunction
to Function in HTML::Timer constructor, which is incorrect because then
callback's captured GC-allocated objects are not protected from being
deallocated. Let's modify HTML::Timer to use JS::HeapFunction for the
callback instead.
By using Core::Timer that accepts Function instead of JS::SafeFunction
in Platform::Timer does we fix memory leak caused by circular
dependency of timer's callback and timer itself.
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.
Instead of using Core::EventLoop and Core::Timer directly, LibWeb now
goes through a Web::Platform abstraction layer instead.
This will allow us to plug in Qt's event loop (and QTimer) over in
Ladybird, to avoid having to deal with multiple event loops.