Bug 1258902 - part2: create service-worker-target component;r=janx

Also added a new utility module aboutdebugging/modules/worker.js
to extract the worker related logic that does not belong in components.

MozReview-Commit-ID: LvArq5cdMtT

devtools/client/aboutdebugging/modules/worker.js

@@ -0,0 +1,77 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const { Task } = require("resource://gre/modules/Task.jsm");
+
+loader.lazyRequireGetter(this, "gDevTools",
+  "devtools/client/framework/devtools", true);
+loader.lazyRequireGetter(this, "TargetFactory",
+  "devtools/client/framework/target", true);
+loader.lazyRequireGetter(this, "Toolbox",
+  "devtools/client/framework/toolbox", true);
+
+/**
+ * Open a window-hosted toolbox to debug the worker associated to the provided
+ * worker actor.
+ *
+ * @param {DebuggerClient} client
+ * @param {Object} workerActor
+ *        worker actor form to debug
+ */
+exports.debugWorker = function(client, workerActor) {
+  client.attachWorker(workerActor, (response, workerClient) => {
+    let workerTarget = TargetFactory.forWorker(workerClient);
+    gDevTools.showToolbox(workerTarget, "jsdebugger", Toolbox.HostType.WINDOW)
+      .then(toolbox => {
+        toolbox.once("destroy", () => workerClient.detach());
+      });
+  });
+};
+
+/**
+ * Retrieve all service worker registrations as well as workers from the parent
+ * and child processes.
+ *
+ * @param {DebuggerClient} client
+ * @return {Object}
+ *         - {Array} registrations
+ *           Array of ServiceWorkerRegistrationActor forms
+ *         - {Array} workers
+ *           Array of WorkerActor forms
+ */
+exports.getWorkerForms = Task.async(function*(client) {
+  let registrations = [];
+  let workers = [];
+
+  try {
+    // List service worker registrations
+    ({ registrations } =
+      yield client.mainRoot.listServiceWorkerRegistrations());
+
+    // List workers from the Parent process
+    ({ workers } = yield client.mainRoot.listWorkers());
+
+    // And then from the Child processes
+    let { processes } = yield client.mainRoot.listProcesses();
+    for (let process of processes) {
+      // Ignore parent process
+      if (process.parent) {
+        continue;
+      }
+      let { form } = yield client.getProcess(process.id);
+      let processActor = form.actor;
+      let response = yield client.request({
+        to: processActor,
+        type: "listWorkers"
+      });
+      workers = workers.concat(response.workers);
+    }
+  } catch (e) {
+    // Something went wrong, maybe our client is disconnected?
+  }
+
+  return { registrations, workers };
+});