Auto merge of #12277 - ConnorGBrewster:network_listener_cancellable, r=Manishearth

Make network listener runnable cancellable

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This keeps scripts from executing after its script thread has been shut down.

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [x] These changes fix (maybe) #12048 (github issue number if applicable).

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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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1 files changed, 3 insertions, 1 deletions

diff --git a/components/script/dom/htmlmediaelement.rs b/components/script/dom/htmlmediaelement.rs
index 7cfe19ba789..877a98311c4 100644
--- a/components/script/dom/htmlmediaelement.rs
+++ b/components/script/dom/htmlmediaelement.rs
@@ -473,10 +473,12 @@ impl HTMLMediaElement {
             // 4.2
             let context = Arc::new(Mutex::new(HTMLMediaElementContext::new(self, url.clone())));
             let (action_sender, action_receiver) = ipc::channel().unwrap();
-            let script_chan = window_from_node(self).networking_task_source();
+            let window = window_from_node(self);
+            let script_chan = window.networking_task_source();
             let listener = box NetworkListener {
                 context: context,
                 script_chan: script_chan,
+                wrapper: Some(window.get_runnable_wrapper()),
             };
 
             let response_target = AsyncResponseTarget {