diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/actors/memory.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/actors/memory.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,95 @@
+/* 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 {Cc, Ci, Cu} = require("chrome");
+let protocol = require("devtools/server/protocol");
+let {method, RetVal} = protocol;
+
+/**
+ * An actor that returns memory usage data for its parent actor's window.
+ * A tab-scoped instance of this actor will measure the memory footprint of its
+ * parent tab. A global-scoped instance however, will measure the memory
+ * footprint of the chrome window referenced by the root actor.
+ */
+let MemoryActor = protocol.ActorClass({
+  typeName: "memory",
+
+  initialize: function(conn, tabActor) {
+    protocol.Actor.prototype.initialize.call(this, conn);
+    this.tabActor = tabActor;
+    this._mgr = Cc["@mozilla.org/memory-reporter-manager;1"]
+                  .getService(Ci.nsIMemoryReporterManager);
+  },
+
+  destroy: function() {
+    this._mgr = null;
+    protocol.Actor.prototype.destroy.call(this);
+  },
+
+  /**
+   * A method that returns a detailed breakdown of the memory consumption of the
+   * associated window.
+   *
+   * @returns object
+   */
+  measure: method(function() {
+    let result = {};
+
+    let jsObjectsSize = {};
+    let jsStringsSize = {};
+    let jsOtherSize = {};
+    let domSize = {};
+    let styleSize = {};
+    let otherSize = {};
+    let totalSize = {};
+    let jsMilliseconds = {};
+    let nonJSMilliseconds = {};
+
+    try {
+      this._mgr.sizeOfTab(this.tabActor.window, jsObjectsSize, jsStringsSize, jsOtherSize,
+                          domSize, styleSize, otherSize, totalSize, jsMilliseconds, nonJSMilliseconds);
+      result.total = totalSize.value;
+      result.domSize = domSize.value;
+      result.styleSize = styleSize.value;
+      result.jsObjectsSize = jsObjectsSize.value;
+      result.jsStringsSize = jsStringsSize.value;
+      result.jsOtherSize = jsOtherSize.value;
+      result.otherSize = otherSize.value;
+      result.jsMilliseconds = jsMilliseconds.value.toFixed(1);
+      result.nonJSMilliseconds = nonJSMilliseconds.value.toFixed(1);
+    } catch (e) {
+      console.error(e);
+      let url = this.tabActor.url;
+      console.error("Error getting size of "+url);
+    }
+
+    return result;
+  }, {
+    request: {},
+    response: RetVal("json"),
+  })
+});
+
+exports.MemoryActor = MemoryActor;
+
+exports.MemoryFront = protocol.FrontClass(MemoryActor, {
+  initialize: function(client, form) {
+    protocol.Front.prototype.initialize.call(this, client, form);
+    this.actorID = form.memoryActor;
+    client.addActorPool(this);
+    this.manage(this);
+  }
+});
+
+exports.register = function(handle) {
+  handle.addGlobalActor(MemoryActor, "memoryActor");
+  handle.addTabActor(MemoryActor, "memoryActor");
+};
+
+exports.unregister = function(handle) {
+  handle.removeGlobalActor(MemoryActor, "memoryActor");
+  handle.removeTabActor(MemoryActor, "memoryActor");
+};