--- a/js/xpconnect/loader/XPCOMUtils.jsm
+++ b/js/xpconnect/loader/XPCOMUtils.jsm
@@ -85,16 +85,18 @@
  *
  * 3. Define the NSGetFactory entry point:
  *  this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);
  */
 
 
 var EXPORTED_SYMBOLS = [ "XPCOMUtils" ];
 
+let global = Cu.getGlobalForObject({});
+
 var XPCOMUtils = {
   /**
    * Generate a QueryInterface implementation. The returned function must be
    * assigned to the 'QueryInterface' property of a JS object. When invoked on
    * that object, it checks if the given iid is listed in the |interfaces|
    * param, and if it is, returns |this| (the object it was called on).
    * If the JS object has a classInfo property it'll be returned for the
    * nsIClassInfo IID, generateCI can be used to generate the classInfo
@@ -225,16 +227,39 @@ var XPCOMUtils = {
         },
         configurable: true,
         enumerable: true
       });
     }
   },
 
   /**
+   * Defines a getter property on the given object for each of the given
+   * global names as accepted by Cu.importGlobalProperties. These
+   * properties are imported into the shared JSM module global, and then
+   * copied onto the given object, no matter which global the object
+   * belongs to.
+   *
+   * @param {object} aObject
+   *        The object on which to define the properties.
+   * @param {string[]} aNames
+   *        The list of global properties to define.
+   */
+  defineLazyGlobalGetters(aObject, aNames) {
+    for (let name of aNames) {
+      this.defineLazyGetter(aObject, name, () => {
+        if (!(name in global)) {
+          Cu.importGlobalProperties([name]);
+        }
+        return global[name];
+      });
+    }
+  },
+
+  /**
    * Defines a getter on a specified object for a service.  The service will not
    * be obtained until first use.
    *
    * @param aObject
    *        The object to define the lazy getter on.
    * @param aName
    *        The name of the getter to define on aObject for the service.
    * @param aContract