Send AsyncJobHandler as a MainThreadTask

components/script/serviceworkerjob.rs

@@ -133,8 +133,10 @@ impl JobQueue {
         if job_queue.is_empty() {
             let scope_url = job.scope_url.clone();
             job_queue.push(job);
-            let run_job_handler = box AsyncJobHandler::new(scope_url);
+            let _ = script_thread.dom_manipulation_task_source().queue_main_thread_task(
-            let _ = script_thread.dom_manipulation_task_source().queue(run_job_handler, global);
+                box AsyncJobHandler::new(scope_url),
+                global,
+            );
             debug!("queued task to run newly-queued job");
         } else {
             // Step 2

components/script/task_source/dom_manipulation.rs

@@ -6,6 +6,7 @@ use dom::bindings::inheritance::Castable;
 use dom::bindings::refcounted::Trusted;
 use dom::event::{EventBubbles, EventCancelable, EventTask, SimpleEventTask};
 use dom::eventtarget::EventTarget;
+use dom::globalscope::GlobalScope;
 use dom::window::Window;
 use script_runtime::{CommonScriptMsg, ScriptThreadEventCategory};
 use script_thread::{MainThreadScriptMsg, Task, TaskCanceller};
@@ -42,6 +43,21 @@ impl TaskSource for DOMManipulationTaskSource {
 }
 
 impl DOMManipulationTaskSource {
+    pub fn queue_main_thread_task<T>(
+        &self,
+        task: Box<T>,
+        global: &GlobalScope,
+    ) -> Result<(), ()>
+    where
+        T: Task + Send + 'static,
+    {
+        let msg = MainThreadScriptMsg::MainThreadTask(
+            ScriptThreadEventCategory::ScriptEvent,
+            global.task_canceller().wrap_task(task),
+        );
+        self.0.send(msg).map_err(|_| ())
+    }
+
     pub fn queue_event(&self,
                        target: &EventTarget,
                        name: Atom,