From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jeremy Apthorp <nornagon@nornagon.net>
Date: Wed, 4 Mar 2020 11:18:03 -0800
Subject: feat: add onclose to MessagePort

This adds the 'onclose' event to MessagePort. Can be removed once
https://bugs.chromium.org/p/chromium/issues/detail?id=1495616 is fixed.

diff --git a/third_party/blink/renderer/core/messaging/message_port.cc b/third_party/blink/renderer/core/messaging/message_port.cc
index 2f2a5b60423af1dbc425c44283cc2f2934bffa18..dbbe04b2447aa0769beca25c60d404b4f2209e43 100644
--- a/third_party/blink/renderer/core/messaging/message_port.cc
+++ b/third_party/blink/renderer/core/messaging/message_port.cc
@@ -195,6 +195,7 @@ void MessagePort::close() {
     Entangle(pipe.TakePort0(), nullptr);
   }
   closed_ = true;
+  DispatchEvent(*Event::Create(event_type_names::kClose));
 }
 
 void MessagePort::Entangle(MessagePortDescriptor port_descriptor,
diff --git a/third_party/blink/renderer/core/messaging/message_port.idl b/third_party/blink/renderer/core/messaging/message_port.idl
index 9df43655b569428a6abc54341b4b0023e159f99b..3f1f181d9b8a66997136f870f55c97c08294b6eb 100644
--- a/third_party/blink/renderer/core/messaging/message_port.idl
+++ b/third_party/blink/renderer/core/messaging/message_port.idl
@@ -40,5 +40,5 @@
     // event handlers
     attribute EventHandler onmessage;
     attribute EventHandler onmessageerror;
-    [RuntimeEnabled=MessagePortCloseEvent] attribute EventHandler onclose;
+    attribute EventHandler onclose;
 };