fix: call setIsTrusted for generated events (MessageEvent) (#19919)

This addresses issue #19918.

## Issue description

Event messages have the wrong isTrusted value when they are not
triggered by user interaction, which differs from the browser. In
particular, all MessageEvents created by Deno have isTrusted set to
false, even though it should be true.

This is my first ever contribution to Deno, so I might be missing
something.

6 files changed, 16 insertions, 3 deletions

diff --git a/ext/broadcast_channel/01_broadcast_channel.js b/ext/broadcast_channel/01_broadcast_channel.js
index d92aef072..ab315eaa6 100644
--- a/ext/broadcast_channel/01_broadcast_channel.js
+++ b/ext/broadcast_channel/01_broadcast_channel.js
@@ -8,6 +8,7 @@ import * as webidl from "ext:deno_webidl/00_webidl.js";
 import {
   defineEventHandler,
   EventTarget,
+  setIsTrusted,
   setTarget,
 } from "ext:deno_web/02_event.js";
 import DOMException from "ext:deno_web/01_dom_exception.js";
@@ -56,6 +57,7 @@ function dispatch(source, name, data) {
         data: core.deserialize(data), // TODO(bnoordhuis) Cache immutables.
         origin: "http://127.0.0.1",
       });
+      setIsTrusted(event, true);
       setTarget(event, channel);
       channel.dispatchEvent(event);
     };
diff --git a/ext/web/13_message_port.js b/ext/web/13_message_port.js
index 08f668b2d..40145db78 100644
--- a/ext/web/13_message_port.js
+++ b/ext/web/13_message_port.js
@@ -14,6 +14,7 @@ import {
   EventTarget,
   MessageEvent,
   setEventTargetData,
+  setIsTrusted,
 } from "ext:deno_web/02_event.js";
 import DOMException from "ext:deno_web/01_dom_exception.js";
 const primordials = globalThis.__bootstrap.primordials;
@@ -155,6 +156,7 @@ class MessagePort extends EventTarget {
           transferables = v[1];
         } catch (err) {
           const event = new MessageEvent("messageerror", { data: err });
+          setIsTrusted(event, true);
           this.dispatchEvent(event);
           return;
         }
@@ -165,6 +167,7 @@ class MessagePort extends EventTarget {
             (t) => ObjectPrototypeIsPrototypeOf(MessagePortPrototype, t),
           ),
         });
+        setIsTrusted(event, true);
         this.dispatchEvent(event);
       }
       this[_enabled] = false;
diff --git a/ext/websocket/01_websocket.js b/ext/websocket/01_websocket.js
index 3f4e16b90..71abb0830 100644
--- a/ext/websocket/01_websocket.js
+++ b/ext/websocket/01_websocket.js
@@ -17,6 +17,7 @@ import {
   Event,
   EventTarget,
   MessageEvent,
+  setIsTrusted,
 } from "ext:deno_web/02_event.js";
 import { Blob, BlobPrototype } from "ext:deno_web/09_file.js";
 import { getLocationHref } from "ext:deno_web/12_location.js";
@@ -430,6 +431,7 @@ class WebSocket extends EventTarget {
             data: op_ws_get_buffer_as_string(rid),
             origin: this[_url],
           });
+          setIsTrusted(event, true);
           dispatch(this, event);
           break;
         }
@@ -450,6 +452,7 @@ class WebSocket extends EventTarget {
             origin: this[_url],
             [_skipInternalInit]: true,
           });
+          setIsTrusted(event, true);
           dispatch(this, event);
           break;
         }
diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index e04690005..f5548d8d1 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -22,6 +22,7 @@ import {
   ErrorEvent,
   EventTarget,
   MessageEvent,
+  setIsTrusted,
 } from "ext:deno_web/02_event.js";
 import {
   deserializeJsMessageData,
@@ -187,6 +188,7 @@ class Worker extends EventTarget {
           cancelable: false,
           data: err,
         });
+        setIsTrusted(event, true);
         this.dispatchEvent(event);
         return;
       }
@@ -198,6 +200,7 @@ class Worker extends EventTarget {
           (t) => ObjectPrototypeIsPrototypeOf(MessagePortPrototype, t),
         ),
       });
+      setIsTrusted(event, true);
       this.dispatchEvent(event);
     }
   };
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index 483ca9012..dc6839646 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -154,6 +154,7 @@ async function pollForMessages() {
           ObjectPrototypeIsPrototypeOf(messagePort.MessagePortPrototype, t),
       ),
     });
+    event.setIsTrusted(msgEvent, true);
 
     try {
       globalDispatchEvent(msgEvent);
@@ -167,6 +168,7 @@ async function pollForMessages() {
         error: e,
       });
 
+      event.setIsTrusted(errorEvent, true);
       globalDispatchEvent(errorEvent);
       if (!errorEvent.defaultPrevented) {
         throw e;
diff --git a/tools/wpt/expectation.json b/tools/wpt/expectation.json
index 946f374eb..19075e224 100644
--- a/tools/wpt/expectation.json
+++ b/tools/wpt/expectation.json
@@ -6399,8 +6399,8 @@
     "Channel_postMessage_with_transfer_incoming_messages.any.worker.html": true,
     "Channel_postMessage_with_transfer_outgoing_messages.any.html": true,
     "Channel_postMessage_with_transfer_outgoing_messages.any.worker.html": true,
-    "MessageEvent-trusted.any.html": false,
-    "MessageEvent-trusted.any.worker.html": false,
+    "MessageEvent-trusted.any.html": true,
+    "MessageEvent-trusted.any.worker.html": true,
     "MessageEvent-trusted.window.html": false,
     "MessageEvent.any.html": true,
     "MessageEvent.any.worker.html": true,
@@ -9688,4 +9688,4 @@
       "media-sniff.window.html": false
     }
   }
-}
\ No newline at end of file
+}