3 files changed, 17 insertions, 13 deletions
diff --git a/components/script/dom/bindings/global.rs b/components/script/dom/bindings/global.rs
index d2b693dbf08..26d7c061503 100644
--- a/components/script/dom/bindings/global.rs
+++ b/components/script/dom/bindings/global.rs
@@ -18,7 +18,7 @@ use js::{JSCLASS_IS_DOMJSCLASS, JSCLASS_IS_GLOBAL};
 use js::glue::{IsWrapper, UnwrapObject};
 use js::jsapi::{CurrentGlobalOrNull, GetGlobalForObjectCrossCompartment};
 use js::jsapi::{JSContext, JSObject, JS_GetClass};
-use script_runtime::{CommonScriptMsg, ScriptChan, ScriptPort};
+use script_runtime::CommonScriptMsg;
 use script_thread::ScriptThread;
 use task_source::file_reading::FileReadingTaskSource;
 
@@ -66,16 +66,6 @@ impl<'a> GlobalRef<'a> {
         }
     }
 
-    /// Create a new sender/receiver pair that can be used to implement an on-demand
-    /// event loop. Used for implementing web APIs that require blocking semantics
-    /// without resorting to nested event loops.
-    pub fn new_script_pair(&self) -> (Box<ScriptChan + Send>, Box<ScriptPort + Send>) {
-        match *self {
-            GlobalRef::Window(ref window) => window.new_script_pair(),
-            GlobalRef::Worker(ref worker) => worker.new_script_pair(),
-        }
-    }
-
     /// Process a single event as if it were the next event in the thread queue for
     /// this global.
     pub fn process_event(&self, msg: CommonScriptMsg) {
diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index cd8fca9a0e4..0b3b609d54b 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -26,7 +26,8 @@ use libc;
 use msg::constellation_msg::PipelineId;
 use net_traits::{CoreResourceThread, ResourceThreads, IpcSend};
 use profile_traits::{mem, time};
-use script_runtime::{EnqueuedPromiseCallback, ScriptChan, maybe_take_panic_result};
+use script_runtime::{EnqueuedPromiseCallback, ScriptChan};
+use script_runtime::{ScriptPort, maybe_take_panic_result};
 use script_thread::{MainThreadScriptChan, RunnableWrapper, ScriptThread};
 use script_traits::{MsDuration, ScriptMsg as ConstellationMsg, TimerEvent};
 use script_traits::{TimerEventId, TimerEventRequest, TimerSource};
@@ -431,6 +432,19 @@ impl GlobalScope {
         }
         unreachable!();
     }
+
+    /// Create a new sender/receiver pair that can be used to implement an on-demand
+    /// event loop. Used for implementing web APIs that require blocking semantics
+    /// without resorting to nested event loops.
+    pub fn new_script_pair(&self) -> (Box<ScriptChan + Send>, Box<ScriptPort + Send>) {
+        if let Some(window) = self.downcast::<Window>() {
+            return window.new_script_pair();
+        }
+        if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
+            return worker.new_script_pair();
+        }
+        unreachable!();
+    }
 }
 
 fn timestamp_in_ms(time: Timespec) -> u64 {
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index 7a586cfe6a1..e8254be3e70 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -1297,7 +1297,7 @@ impl XMLHttpRequest {
 
         let global_scope = global.as_global_scope();
         let (script_chan, script_port) = if self.sync.get() {
-            let (tx, rx) = global.new_script_pair();
+            let (tx, rx) = global_scope.new_script_pair();
             (tx, Some(rx))
         } else {
             (global_scope.networking_task_source(), None)