DOMRectList interface implementation (#34025)

* rechecking all file changes and additions

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* added comments with specification links

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* added space before the links

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* modified the doc link format

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* suggested changes + updated interfaces.https.html + updated passing test expectations

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* needed to do an update-manifest

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

* updated the idlharness.any.html expectations

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

---------

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

components/script/dom/domrectlist.rs

@@ -0,0 +1,66 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+use dom_struct::dom_struct;
+
+use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::DOMRectListBinding::DOMRectListMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object_with_proto, DomObject, Reflector};
+use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::domrect::DOMRect;
+use crate::dom::window::Window;
+use crate::script_runtime::CanGc;
+
+#[dom_struct]
+pub struct DOMRectList {
+    reflector_: Reflector,
+    rects: DomRefCell<Vec<Dom<DOMRect>>>,
+}
+
+impl DOMRectList {
+    fn new_inherited(rects: Vec<DomRoot<DOMRect>>) -> DOMRectList {
+        DOMRectList {
+            reflector_: Reflector::new(),
+            rects: DomRefCell::new(
+                rects
+                    .into_iter()
+                    .map(|dom_root| dom_root.as_traced())
+                    .collect(),
+            ),
+        }
+    }
+
+    pub fn new(
+        window: &Window,
+        rects: Vec<DomRoot<DOMRect>>,
+        can_gc: CanGc,
+    ) -> DomRoot<DOMRectList> {
+        reflect_dom_object_with_proto(
+            Box::new(DOMRectList::new_inherited(rects)),
+            &*window.global(),
+            None,
+            can_gc,
+        )
+    }
+
+    pub fn first(&self) -> Option<DomRoot<DOMRect>> {
+        self.rects.borrow().first().map(Dom::as_rooted)
+    }
+}
+
+impl DOMRectListMethods for DOMRectList {
+    /// <https://drafts.fxtf.org/geometry/#DOMRectList>
+    fn Item(&self, index: u32) -> Option<DomRoot<DOMRect>> {
+        self.rects.borrow().get(index as usize).map(Dom::as_rooted)
+    }
+
+    /// <https://drafts.fxtf.org/geometry/#DOMRectList>
+    fn IndexedGetter(&self, index: u32) -> Option<DomRoot<DOMRect>> {
+        self.Item(index)
+    }
+
+    /// <https://drafts.fxtf.org/geometry/#DOMRectList>
+    fn Length(&self) -> u32 {
+        self.rects.borrow().len() as u32
+    }
+}