Properly root the running animation list in a RootedVec

components/script/dom/bindings/trace.rs

@@ -668,11 +668,25 @@ pub struct RootedVec<'a, T: 'static + JSTraceable> {
     root: &'a mut RootableVec<T>,
 }
 
-impl<'a, T: 'static + JSTraceable + DomObject> RootedVec<'a, JS<T>> {
+impl<'a, T: 'static + JSTraceable> RootedVec<'a, T> {
     /// Create a vector of items of type T that is rooted for
     /// the lifetime of this struct
-    pub fn new<I: Iterator<Item = Root<T>>>(root: &'a mut RootableVec<JS<T>>, iter: I)
+    pub fn new(root: &'a mut RootableVec<T>) -> Self {
-                                            -> RootedVec<'a, JS<T>> {
+        unsafe {
+            RootedTraceableSet::add(root);
+        }
+        RootedVec {
+            root: root,
+        }
+    }
+}
+
+impl<'a, T: 'static + JSTraceable + DomObject> RootedVec<'a, JS<T>> {
+    /// Create a vector of items of type JS<T> that is rooted for
+    /// the lifetime of this struct
+    pub fn from_iter<I>(root: &'a mut RootableVec<JS<T>>, iter: I) -> Self
+        where I: Iterator<Item = Root<T>>
+    {
         unsafe {
             RootedTraceableSet::add(root);
         }

components/script/dom/document.rs

@@ -1521,8 +1521,11 @@ impl Document {
 
     /// https://html.spec.whatwg.org/multipage/#run-the-animation-frame-callbacks
     pub fn run_the_animation_frame_callbacks(&self) {
-        let mut animation_frame_list =
+        rooted_vec!(let mut animation_frame_list);
-            mem::replace(&mut *self.animation_frame_list.borrow_mut(), vec![]);
+        mem::swap(
+            &mut *animation_frame_list,
+            &mut *self.animation_frame_list.borrow_mut());
+
         self.running_animation_callbacks.set(true);
         let timing = self.window.Performance().Now();
 
@@ -1538,7 +1541,7 @@ impl Document {
         // message quickly followed by an AnimationCallbacksPresent message.
         if self.animation_frame_list.borrow().is_empty() {
             mem::swap(&mut *self.animation_frame_list.borrow_mut(),
-                      &mut animation_frame_list);
+                      &mut *animation_frame_list);
             let global_scope = self.window.upcast::<GlobalScope>();
             let event = ConstellationMsg::ChangeRunningAnimationsState(global_scope.pipeline_id(),
                                                                        AnimationState::NoAnimationCallbacksPresent);

components/script/dom/macros.rs

@@ -537,14 +537,15 @@ macro_rules! document_and_element_event_handlers(
 #[macro_export]
 macro_rules! rooted_vec {
     (let mut $name:ident) => {
-        rooted_vec!(let mut $name <- ::std::iter::empty())
+        let mut root = $crate::dom::bindings::trace::RootableVec::new_unrooted();
+        let mut $name = $crate::dom::bindings::trace::RootedVec::new(&mut root);
     };
     (let $name:ident <- $iter:expr) => {
-        let mut __root = $crate::dom::bindings::trace::RootableVec::new_unrooted();
+        let mut root = $crate::dom::bindings::trace::RootableVec::new_unrooted();
-        let $name = $crate::dom::bindings::trace::RootedVec::new(&mut __root, $iter);
+        let $name = $crate::dom::bindings::trace::RootedVec::from_iter(&mut root, $iter);
     };
     (let mut $name:ident <- $iter:expr) => {
-        let mut __root = $crate::dom::bindings::trace::RootableVec::new_unrooted();
+        let mut root = $crate::dom::bindings::trace::RootableVec::new_unrooted();
-        let mut $name = $crate::dom::bindings::trace::RootedVec::new(&mut __root, $iter);
+        let mut $name = $crate::dom::bindings::trace::RootedVec::from_iter(&mut root, $iter);
     }
 }