Rename shim -> cast

ext/src/cast/contentBridge.ts

@@ -0,0 +1,21 @@
+"use strict";
+
+import { onMessageResponse, sendMessage } from "./eventMessageChannel";
+
+import messaging, { Message } from "../messaging";
+
+// Message port to background script
+export const backgroundPort = messaging.connect({ name: "cast" });
+
+const forwardToCast = (message: Message) => sendMessage(message);
+const forwardToMain = (message: Message) => backgroundPort.postMessage(message);
+
+// Add message listeners
+backgroundPort.onMessage.addListener(forwardToCast);
+const listener = onMessageResponse(forwardToMain);
+
+// Remove listeners
+backgroundPort.onDisconnect.addListener(() => {
+    backgroundPort.onMessage.removeListener(forwardToCast);
+    listener.disconnect();
+});