diff -r 000000000000 -r 6474c204b198 b2g/components/SimulatorScreen.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/b2g/components/SimulatorScreen.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,117 @@
+/* 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/. */
+
+let Ci = Components.interfaces;
+let Cu = Components.utils;
+
+Cu.import('resource://gre/modules/XPCOMUtils.jsm');
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://gre/modules/DOMRequestHelper.jsm');
+
+XPCOMUtils.defineLazyModuleGetter(this, 'GlobalSimulatorScreen',
+                                  'resource://gre/modules/GlobalSimulatorScreen.jsm');
+
+let DEBUG_PREFIX = 'SimulatorScreen.js - ';
+function debug() {
+  //dump(DEBUG_PREFIX + Array.slice(arguments) + '\n');
+}
+
+function fireOrientationEvent(window) {
+  let e = new window.Event('mozorientationchange');
+  window.screen.dispatchEvent(e);
+}
+
+function hookScreen(window) {
+  let nodePrincipal = window.document.nodePrincipal;
+  let origin = nodePrincipal.origin;
+  if (nodePrincipal.appStatus == nodePrincipal.APP_STATUS_NOT_INSTALLED) {
+    Cu.reportError('deny mozLockOrientation:' + origin + 'is not installed');
+    return;
+  }
+
+  let screen = window.wrappedJSObject.screen;
+
+  screen.mozLockOrientation = function (orientation) {
+    debug('mozLockOrientation:', orientation, 'from', origin);
+
+    // Normalize and do some checks against orientation input
+    if (typeof(orientation) == 'string') {
+      orientation = [orientation];
+    }
+
+    function isInvalidOrientationString(str) {
+      return typeof(str) != 'string' ||
+        !str.match(/^default$|^(portrait|landscape)(-(primary|secondary))?$/);
+    }
+    if (!Array.isArray(orientation) ||
+        orientation.some(isInvalidOrientationString)) {
+      Cu.reportError('Invalid orientation "' + orientation + '"');
+      return false;
+    }
+
+    GlobalSimulatorScreen.lock(orientation);
+
+    return true;
+  };
+
+  screen.mozUnlockOrientation = function() {
+    debug('mozOrientationUnlock from', origin);
+    GlobalSimulatorScreen.unlock();
+    return true;
+  };
+
+  Object.defineProperty(screen, 'width', {
+    get: function () GlobalSimulatorScreen.width
+  });
+  Object.defineProperty(screen, 'height', {
+    get: function () GlobalSimulatorScreen.height
+  });
+  Object.defineProperty(screen, 'mozOrientation', {
+    get: function () GlobalSimulatorScreen.mozOrientation
+  });
+}
+
+function SimulatorScreen() {}
+SimulatorScreen.prototype = {
+  classID:         Components.ID('{c83c02c0-5d43-4e3e-987f-9173b313e880}'),
+  QueryInterface:  XPCOMUtils.generateQI([Ci.nsIObserver,
+                                          Ci.nsISupportsWeakReference]),
+  _windows: new Map(),
+
+  observe: function (subject, topic, data) {
+    let windows = this._windows;
+    switch (topic) {
+      case 'profile-after-change':
+        Services.obs.addObserver(this, 'document-element-inserted', false);
+        Services.obs.addObserver(this, 'simulator-orientation-change', false);
+        Services.obs.addObserver(this, 'inner-window-destroyed', false);
+        break;
+
+      case 'document-element-inserted':
+        let window = subject.defaultView;
+        if (!window) {
+          return;
+        }
+
+        hookScreen(window);
+
+        var id = window.QueryInterface(Ci.nsIInterfaceRequestor)
+                       .getInterface(Ci.nsIDOMWindowUtils)
+                       .currentInnerWindowID;
+        windows.set(id, window);
+        break;
+
+      case 'inner-window-destroyed':
+        var id = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+        windows.delete(id);
+        break;
+
+      case 'simulator-orientation-change':
+        windows.forEach(fireOrientationEvent);
+        break;
+    }
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SimulatorScreen]);