Implement binding support for returning and accepting Promises in WebIDL.

components/script/dom/testbinding.rs

@@ -28,6 +28,7 @@ use dom::bindings::reflector::{Reflectable, Reflector, reflect_dom_object};
 use dom::bindings::str::{ByteString, DOMString, USVString};
 use dom::bindings::weakref::MutableWeakRef;
 use dom::blob::{Blob, BlobImpl};
+use dom::promise::Promise;
 use dom::url::URL;
 use js::jsapi::{HandleObject, HandleValue, JSContext, JSObject};
 use js::jsapi::{JS_NewPlainObject, JS_NewUint8ClampedArray};
@@ -647,6 +648,22 @@ impl TestBindingMethods for TestBinding {
     fn ReceiveMozMapOfMozMaps(&self) -> MozMap<MozMap<i32>> { MozMap::new() }
     fn ReceiveAnyMozMap(&self) -> MozMap<JSVal> { MozMap::new() }
 
+    #[allow(unrooted_must_root)]
+    fn ReturnPromise(&self) -> Rc<Promise> {
+        Promise::new(self.global().r())
+    }
+
+    #[allow(unrooted_must_root)]
+    fn PromiseAttribute(&self) -> Rc<Promise> {
+        Promise::new(self.global().r())
+    }
+
+    fn AcceptPromise(&self, _promise: &Promise) {
+    }
+
+    fn AcceptNullablePromise(&self, _promise: Option<&Promise>) {
+    }
+
     fn PassSequenceSequence(&self, _seq: Vec<Vec<i32>>) {}
     fn ReturnSequenceSequence(&self) -> Vec<Vec<i32>> { vec![] }
     fn PassUnionSequenceSequence(&self, seq: LongOrLongSequenceSequence) {