Reject connection attempts without prompt if target app doesn't handle the event anyway.

extensions/common/api/runtime.json

Index: extensions/common/api/runtime.json
diff --git a/extensions/common/api/runtime.json b/extensions/common/api/runtime.json
index 009769f8fc8bebfbaf995a83f492f6b20b06b7ca..222267748ef5653261c3609ace0660bb26742702 100644
--- a/extensions/common/api/runtime.json
+++ b/extensions/common/api/runtime.json
@@ -424,9 +424,6 @@
         "name": "onConnectExternal",
         "type": "function",
         "nocompile": true,
-        "options": {
-          "unmanaged": true
-        },
         "description": "Fired when a connection is made from another extension.",
         "parameters": [
           {"$ref": "Port", "name": "port"}
@@ -435,10 +432,10 @@
       {
         "name": "onMessage",
         "type": "function",
+        "nocompile": true,
         "options": {
           "unmanaged": true
         },
-        "nocompile": true,
         "description": "Fired when a message is sent from either an extension process or a content script.",
         "parameters": [
           {"name": "message", "type": "any", "optional": true, "description": "The message sent by the calling script."},
@@ -454,9 +451,6 @@
       {
         "name": "onMessageExternal",
         "type": "function",
-        "options": {
-          "unmanaged": true
-        },
         "nocompile": true,
         "description": "Fired when a message is sent from another extension/app. Cannot be used in a content script.",
         "parameters": [