script: Move `TaskManager` to `GlobalScope` (#34827)

This is a simplification of the internal `TaskQueue` API that moves the
`TaskManager` to the `GlobalScope` itself. In addition, the handling of
cancellers is moved to the `TaskManager` as well. This means that no
arguments other than the `task` are necessary for queueing tasks, which
makes the API a lot easier to use and cleaner.

`TaskSource` now also keeps a copy of the canceller with it, so that
they always know the proper way to cancel any tasks queued on them.

There is one complication here. The event loop `sender` for dedicated
workers is constantly changing as it is set to `None` when not handling
messages. This is because this sender keeps a handle to the main
thread's `Worker` object, preventing garbage collection while any
messages are still in flight or being handled. This change allows
setting the `sender` on the `TaskManager` to `None` to allow proper
garbabge collection.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/components/script/dom/textcontrol.rs b/components/script/dom/textcontrol.rs
index 7e94e404d40..6fab849a17c 100644
--- a/components/script/dom/textcontrol.rs
+++ b/components/script/dom/textcontrol.rs
@@ -300,8 +300,8 @@ impl<'a, E: TextControlElement> TextControlSelection<'a, E> {
 
         // Step 6
         if textinput.selection_state() != original_selection_state {
-            let window = self.element.owner_window();
-            window
+            self.element
+                .owner_window()
                 .task_manager()
                 .user_interaction_task_source()
                 .queue_event(
@@ -309,7 +309,6 @@ impl<'a, E: TextControlElement> TextControlSelection<'a, E> {
                     atom!("select"),
                     EventBubbles::Bubbles,
                     EventCancelable::NotCancelable,
-                    &window,
                 );
         }