This avoids an unnecessary lossy conversion for the current time from
double to i32. And avoids an UBSAN failure on macOS that's dependent
on the current uptime.
(cherry picked from commit 55c1b5d1f4d7c82f0a68323260cb2e0f7de2faae,
amended to fix a typo in the commit message)
From https://html.spec.whatwg.org/#list-of-animation-frame-callbacks:
Each target object has a map of animation frame callbacks, which is
an ordered map that must be initially empty, and an animation frame
callback identifier, which is a number that must initially be zero.
Previously, 'now' was set to the time `requestAnimationFrame()` was
called, and the EventLoop's 'now' was ignored. This was a little odd and
meant the time was always in the past.
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.
Previously requestAnimationFrame() callbacks were registered with a
static global RequestAnimationFrameDriver shared between all windows.
This led to callbacks still running after navigating away from a page
(This could be seen with the WASM GoL demo).
This commit moves the RequestAnimationFrameDriver (now
AnimationFrameCallbackDriver) to be a member of the HTML::Window
object, then uses the 'active document' parameter of
run_animation_frame_callbacks() to run only the active callbacks.
