begin messageport, transferable objects, impl

Accept transfer argument for StructuredCloneData::write

Allow structured clone reads to return a boolean

Add Transferable trait

Add basic skeletons to MessagePort

Implement transfer and transfer-receiving steps on MessagePort

Use transfer and transfer_receive in StructuredClone callbacks

Implement MessageChannel

Freeze the array object for the MessageEvent ports attribute

Implement transfer argument on window.postMessage

Use ReentrantMutex instead for MessagePortInternal

Accept origin as a parameter in dispatch_jsval

Fix BorrowMut crash with pending_port_message

Detach port on closure and check for detached during transfer

Enable webmessaging tests

fix webidl

fix

components/script/dom/bindings/transferable.rs

@@ -0,0 +1,29 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+//! Trait representing the concept of [transferable objects]
+//! (https://html.spec.whatwg.org/multipage/#transferable-objects).
+use crate::dom::bindings::reflector::DomObject;
+use js::jsapi::{JSContext, JSStructuredCloneReader, MutableHandleObject};
+use std::os::raw;
+
+pub trait Transferable : DomObject {
+    fn transfer(
+        &self,
+        closure: *mut raw::c_void,
+        content: *mut *mut raw::c_void,
+        extra_data: *mut u64,
+    ) -> bool;
+    fn transfer_receive(
+        cx: *mut JSContext,
+        r: *mut JSStructuredCloneReader,
+        closure: *mut raw::c_void,
+        content: *mut raw::c_void,
+        extra_data: u64,
+        return_object: MutableHandleObject,
+    ) -> bool;
+    fn detached(&self) -> Option<bool> { None }
+    fn set_detached(&self, _value: bool) { }
+    fn transferable(&self) -> bool { false }
+}