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
http://www.robohornet.org gives a score of 101.36 on master,
and 102.68 with this PR. The latter is slightly better,
but probably within noise level.
So it looks like this PR does not affect DOM performance.
This is expected since `Box::new` is defined as:
```rust
impl<T> Box<T> {
#[inline(always)]
pub fn new(x: T) -> Box<T> {
box x
}
}
```
With inlining, it should compile to the same as box syntax.
