diff -r 000000000000 -r 6474c204b198 testing/mochitest/tests/SimpleTest/ChromePowers.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/mochitest/tests/SimpleTest/ChromePowers.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,104 @@
+/* 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/. */
+
+function ChromePowers(window) {
+  this.window = Components.utils.getWeakReference(window);
+
+  // In the case of browser-chrome tests, we are running as a [ChromeWindow]
+  // and we have no window.QueryInterface available, content.window is what we need
+  if (typeof(window) == "ChromeWindow" && typeof(content.window) == "Window") {
+    this.DOMWindowUtils = bindDOMWindowUtils(content.window);
+    this.window = Components.utils.getWeakReference(content.window);
+  } else {
+    this.DOMWindowUtils = bindDOMWindowUtils(window);
+  }
+
+  this.spObserver = new SpecialPowersObserverAPI();
+}
+
+ChromePowers.prototype = new SpecialPowersAPI();
+
+ChromePowers.prototype.toString = function() { return "[ChromePowers]"; };
+ChromePowers.prototype.sanityCheck = function() { return "foo"; };
+
+// This gets filled in in the constructor.
+ChromePowers.prototype.DOMWindowUtils = undefined;
+
+ChromePowers.prototype._sendSyncMessage = function(type, msg) {
+  var aMessage = {'name':type, 'json': msg};
+  return [this._receiveMessage(aMessage)];
+};
+
+ChromePowers.prototype._sendAsyncMessage = function(type, msg) {
+  var aMessage = {'name':type, 'json': msg};
+  this._receiveMessage(aMessage);
+};
+
+ChromePowers.prototype.registerProcessCrashObservers = function() {
+  this._sendSyncMessage("SPProcessCrashService", { op: "register-observer" });
+};
+
+ChromePowers.prototype.unregisterProcessCrashObservers = function() {
+  this._sendSyncMessage("SPProcessCrashService", { op: "unregister-observer" });
+};
+
+ChromePowers.prototype._receiveMessage = function(aMessage) {
+  switch (aMessage.name) {
+    case "SpecialPowers.Quit":
+      let appStartup = Cc["@mozilla.org/toolkit/app-startup;1"].getService(Ci.nsIAppStartup);
+      appStartup.quit(Ci.nsIAppStartup.eForceQuit);
+      break;
+    case "SPProcessCrashService":
+      if (aMessage.json.op == "register-observer" || aMessage.json.op == "unregister-observer") {
+        // Hack out register/unregister specifically for browser-chrome leaks
+        break;
+      } else if (aMessage.type == "crash-observed") {
+        for (let e of msg.dumpIDs) {
+          this._encounteredCrashDumpFiles.push(e.id + "." + e.extension);
+        }
+      }
+    default:
+      // All calls go here, because we need to handle SPProcessCrashService calls as well
+      return this.spObserver._receiveMessageAPI(aMessage);
+  }
+  return undefined;		// Avoid warning.
+};
+
+ChromePowers.prototype.quit = function() {
+  // We come in here as SpecialPowers.quit, but SpecialPowers is really ChromePowers.
+  // For some reason this.<func> resolves to TestRunner, so using SpecialPowers
+  // allows us to use the ChromePowers object which we defined below.
+  SpecialPowers._sendSyncMessage("SpecialPowers.Quit", {});
+};
+
+ChromePowers.prototype.focus = function(aWindow) {
+  // We come in here as SpecialPowers.focus, but SpecialPowers is really ChromePowers.
+  // For some reason this.<func> resolves to TestRunner, so using SpecialPowers
+  // allows us to use the ChromePowers object which we defined below.
+  if (aWindow)
+    aWindow.focus();
+};
+
+ChromePowers.prototype.executeAfterFlushingMessageQueue = function(aCallback) {
+  aCallback();
+};
+
+// Expose everything but internal APIs (starting with underscores) to
+// web content.  We cannot use Object.keys to view SpecialPowers.prototype since
+// we are using the functions from SpecialPowersAPI.prototype
+ChromePowers.prototype.__exposedProps__ = {};
+for (var i in ChromePowers.prototype) {
+  if (i.charAt(0) != "_")
+    ChromePowers.prototype.__exposedProps__[i] = "r";
+}
+
+if ((window.parent !== null) &&
+    (window.parent !== undefined) &&
+    (window.parent.wrappedJSObject.SpecialPowers) &&
+    !(window.wrappedJSObject.SpecialPowers)) {
+  window.wrappedJSObject.SpecialPowers = window.parent.SpecialPowers;
+} else {
+  window.wrappedJSObject.SpecialPowers = new ChromePowers(window);
+}
+