diff -r 000000000000 -r 6474c204b198 webapprt/content/dbg-webapp-actors.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webapprt/content/dbg-webapp-actors.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,126 @@
+/* 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 { Promise } = Cu.import("resource://gre/modules/Promise.jsm", {});
+
+/**
+ * WebappRT-specific actors.
+ */
+
+/**
+ * Construct a root actor appropriate for use in a server running in the webapp
+ * runtime. The returned root actor:
+ * - respects the factories registered with DebuggerServer.addGlobalActor,
+ * - uses a WebappTabList to supply tab actors,
+ * - sends all webapprt:webapp window documents a Debugger:Shutdown event
+ *   when it exits.
+ *
+ * * @param connection DebuggerServerConnection
+ *        The conection to the client.
+ */
+function createRootActor(connection)
+{
+  let parameters = {
+    tabList: new WebappTabList(connection),
+    globalActorFactories: DebuggerServer.globalActorFactories,
+    onShutdown: sendShutdownEvent
+  };
+  return new RootActor(connection, parameters);
+}
+
+/**
+ * A live list of BrowserTabActors representing the current webapp windows,
+ * to be provided to the root actor to answer 'listTabs' requests. In the
+ * webapp runtime, only a single tab per window is ever present.
+ *
+ * @param connection DebuggerServerConnection
+ *     The connection in which this list's tab actors may participate.
+ *
+ * @see BrowserTabList for more a extensive description of how tab list objects
+ *      work.
+ */
+function WebappTabList(connection)
+{
+  BrowserTabList.call(this, connection);
+}
+
+WebappTabList.prototype = Object.create(BrowserTabList.prototype);
+
+WebappTabList.prototype.constructor = WebappTabList;
+
+WebappTabList.prototype.getList = function() {
+  let topXULWindow = Services.wm.getMostRecentWindow(this._windowType);
+
+  // As a sanity check, make sure all the actors presently in our map get
+  // picked up when we iterate over all windows.
+  let initialMapSize = this._actorByBrowser.size;
+  let foundCount = 0;
+
+  // To avoid mysterious behavior if windows are closed or opened mid-iteration,
+  // we update the map first, and then make a second pass over it to yield
+  // the actors. Thus, the sequence yielded is always a snapshot of the
+  // actors that were live when we began the iteration.
+
+  // Iterate over all webapprt:webapp XUL windows.
+  for (let win of allAppShellDOMWindows(this._windowType)) {
+    let browser = win.document.getElementById("content");
+    if (!browser) {
+      continue;
+    }
+
+    // Do we have an existing actor for this browser? If not, create one.
+    let actor = this._actorByBrowser.get(browser);
+    if (actor) {
+      foundCount++;
+    } else {
+      actor = new WebappTabActor(this._connection, browser);
+      this._actorByBrowser.set(browser, actor);
+    }
+
+    actor.selected = (win == topXULWindow);
+  }
+
+  if (this._testing && initialMapSize !== foundCount) {
+    throw Error("_actorByBrowser map contained actors for dead tabs");
+  }
+
+  this._mustNotify = true;
+  this._checkListening();
+
+  return Promise.resolve([actor for ([_, actor] of this._actorByBrowser)]);
+};
+
+/**
+ * Creates a tab actor for handling requests to the single tab, like
+ * attaching and detaching. WebappTabActor respects the actor factories
+ * registered with DebuggerServer.addTabActor.
+ *
+ * We override the title of the XUL window in content/webapp.js so here
+ * we need to override the title property to avoid confusion to the user.
+ * We won't return the title of the contained browser, but the title of
+ * the webapp window.
+ *
+ * @param connection DebuggerServerConnection
+ *        The conection to the client.
+ * @param browser browser
+ *        The browser instance that contains this tab.
+ */
+function WebappTabActor(connection, browser)
+{
+  BrowserTabActor.call(this, connection, browser);
+}
+
+WebappTabActor.prototype.constructor = WebappTabActor;
+
+WebappTabActor.prototype = Object.create(BrowserTabActor.prototype);
+
+Object.defineProperty(WebappTabActor.prototype, "title", {
+  get: function() {
+    return this.browser.ownerDocument.defaultView.document.title;
+  },
+  enumerable: true,
+  configurable: false
+});