eclipse-che/che#9063 add simple worker script and frontend module

Signed-off-by: Yevhen Vydolob <yvydolob@redhat.com>

packages/isolated-extension-api/package.json

@@ -10,7 +10,8 @@
   },
   "theiaExtensions": [
     {
-      "backend": "lib/node/extension-api-backend-module"
+      "backend": "lib/node/extension-api-backend-module",
+      "frontend": "lib/browser/extension-api-frontend-module"
     }
   ],
   "keywords": [

packages/isolated-extension-api/src/browser/extension-api-frontend-module.ts

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2015-2018 Red Hat, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+import { ContainerModule } from "inversify";
+import { FrontendApplicationContribution, FrontendApplication } from "@theia/core/lib/browser";
+import { MaybePromise } from "@theia/core/lib/common";
+
+export default new ContainerModule(bind => {
+    bind(FrontendApplicationContribution).toDynamicValue(ctx => ({
+        onStart(app: FrontendApplication): MaybePromise<void> {
+            const worker = new Worker('/webworker/worker-main.ts');
+            worker.addEventListener('message', message => {
+                console.log(message);
+            });
+        }
+    }));
+});

packages/isolated-extension-api/src/worker/worker-main.ts

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2018 Red Hat, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Red Hat, Inc. - initial API and implementation
+ */
+
+import { RPCProtocolImpl, createExtensionProxyIdentifier } from '../api/rpc-protocol';
+import { Emitter } from '@theia/core/lib/common/event';
+import { Disposable } from '@theia/core/lib/common/disposable';
+export interface MainThreadCommandsShape extends Disposable {
+    $registerCommand(id: string): void;
+    $unregisterCommand(id: string): void;
+    $executeCommand<T>(id: string, args: any[]): Thenable<T>;
+    $getCommands(): Thenable<string[]>;
+}
+
+const emmitter = new Emitter();
+const rpc = new RPCProtocolImpl({
+    onMessage: emmitter.event,
+    send: (m: {}) => {
+        postMessage(m);
+    }
+});
+addEventListener('message', (message: any) => {
+    emmitter.fire(message.data);
+});
+
+const ExtHostCommands = createExtensionProxyIdentifier<MainThreadCommandsShape>("MainThreadCommands");
+
+const proxy = rpc.getProxy(ExtHostCommands);
+
+proxy.$registerCommand('foo');