diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/actors/common.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/actors/common.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,168 @@
+/* -*- tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* 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";
+
+/**
+ * Methods shared between RootActor and BrowserTabActor.
+ */
+
+/**
+ * Populate |this._extraActors| as specified by |aFactories|, reusing whatever
+ * actors are already there. Add all actors in the final extra actors table to
+ * |aPool|.
+ *
+ * The root actor and the tab actor use this to instantiate actors that other
+ * parts of the browser have specified with DebuggerServer.addTabActor antd
+ * DebuggerServer.addGlobalActor.
+ *
+ * @param aFactories
+ *     An object whose own property names are the names of properties to add to
+ *     some reply packet (say, a tab actor grip or the "listTabs" response
+ *     form), and whose own property values are actor constructor functions, as
+ *     documented for addTabActor and addGlobalActor.
+ *
+ * @param this
+ *     The BrowserRootActor or BrowserTabActor with which the new actors will
+ *     be associated. It should support whatever API the |aFactories|
+ *     constructor functions might be interested in, as it is passed to them.
+ *     For the sake of CommonCreateExtraActors itself, it should have at least
+ *     the following properties:
+ *
+ *     - _extraActors
+ *        An object whose own property names are factory table (and packet)
+ *        property names, and whose values are no-argument actor constructors,
+ *        of the sort that one can add to an ActorPool.
+ *
+ *     - conn
+ *        The DebuggerServerConnection in which the new actors will participate.
+ *
+ *     - actorID
+ *        The actor's name, for use as the new actors' parentID.
+ */
+exports.createExtraActors = function createExtraActors(aFactories, aPool) {
+  // Walk over global actors added by extensions.
+  for (let name in aFactories) {
+    let actor = this._extraActors[name];
+    if (!actor) {
+      actor = aFactories[name].bind(null, this.conn, this);
+      actor.prototype = aFactories[name].prototype;
+      actor.parentID = this.actorID;
+      this._extraActors[name] = actor;
+    }
+    aPool.addActor(actor);
+  }
+}
+
+/**
+ * Append the extra actors in |this._extraActors|, constructed by a prior call
+ * to CommonCreateExtraActors, to |aObject|.
+ *
+ * @param aObject
+ *     The object to which the extra actors should be added, under the
+ *     property names given in the |aFactories| table passed to
+ *     CommonCreateExtraActors.
+ *
+ * @param this
+ *     The BrowserRootActor or BrowserTabActor whose |_extraActors| table we
+ *     should use; see above.
+ */
+exports.appendExtraActors = function appendExtraActors(aObject) {
+  for (let name in this._extraActors) {
+    let actor = this._extraActors[name];
+    aObject[name] = actor.actorID;
+  }
+}
+
+/**
+ * Construct an ActorPool.
+ *
+ * ActorPools are actorID -> actor mapping and storage.  These are
+ * used to accumulate and quickly dispose of groups of actors that
+ * share a lifetime.
+ */
+function ActorPool(aConnection)
+{
+  this.conn = aConnection;
+  this._cleanups = {};
+  this._actors = {};
+}
+
+ActorPool.prototype = {
+  /**
+   * Add an actor to the actor pool.  If the actor doesn't have an ID,
+   * allocate one from the connection.
+   *
+   * @param aActor object
+   *        The actor implementation.  If the object has a
+   *        'disconnect' property, it will be called when the actor
+   *        pool is cleaned up.
+   */
+  addActor: function AP_addActor(aActor) {
+    aActor.conn = this.conn;
+    if (!aActor.actorID) {
+      let prefix = aActor.actorPrefix;
+      if (typeof aActor == "function") {
+        // typeName is a convention used with protocol.js-based actors
+        prefix = aActor.prototype.actorPrefix || aActor.prototype.typeName;
+      }
+      aActor.actorID = this.conn.allocID(prefix || undefined);
+    }
+
+    if (aActor.registeredPool) {
+      aActor.registeredPool.removeActor(aActor);
+    }
+    aActor.registeredPool = this;
+
+    this._actors[aActor.actorID] = aActor;
+    if (aActor.disconnect) {
+      this._cleanups[aActor.actorID] = aActor;
+    }
+  },
+
+  get: function AP_get(aActorID) {
+    return this._actors[aActorID];
+  },
+
+  has: function AP_has(aActorID) {
+    return aActorID in this._actors;
+  },
+
+  /**
+   * Returns true if the pool is empty.
+   */
+  isEmpty: function AP_isEmpty() {
+    return Object.keys(this._actors).length == 0;
+  },
+
+  /**
+   * Remove an actor from the actor pool.
+   */
+  removeActor: function AP_remove(aActor) {
+    delete this._actors[aActor.actorID];
+    delete this._cleanups[aActor.actorID];
+  },
+
+  /**
+   * Match the api expected by the protocol library.
+   */
+  unmanage: function(aActor) {
+    return this.removeActor(aActor);
+  },
+
+  /**
+   * Run all actor cleanups.
+   */
+  cleanup: function AP_cleanup() {
+    for each (let actor in this._cleanups) {
+      actor.disconnect();
+    }
+    this._cleanups = {};
+  }
+}
+
+exports.ActorPool = ActorPool;
+