diff -r 000000000000 -r 6474c204b198 js/xpconnect/idl/mozIJSSubScriptLoader.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/idl/mozIJSSubScriptLoader.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * 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/. */
+
+#include "nsISupports.idl"
+
+interface nsIURI;
+interface nsIPrincipal;
+interface nsIObserver;
+
+[scriptable, uuid(19533e7b-f321-4ef1-bc59-6e812dc2a733)]
+interface mozIJSSubScriptLoader : nsISupports
+{
+    /**
+     * This method should only be called from JS!
+     * In JS, the signature looks like:
+     * rv loadSubScript (url [, obj] [, charset]);
+     * @param url the url of the sub-script, it MUST be either a file:,
+     *            resource:, or chrome: url, and MUST be local.
+     * @param obj an optional object to evaluate the script onto, it
+     *            defaults to the global object of the caller.
+     * @param charset optionally specifies the character encoding of
+     *                the file. If absent, the file is interpreted
+     *                as ASCII.
+     * @retval rv the value returned by the sub-script
+     */
+    [implicit_jscontext]
+    jsval loadSubScript(in AString url, [optional] in jsval obj, [optional] in AString charset);
+
+    /**
+     * This method should only be called from JS!
+     * In JS, the signature looks like:
+     * rv = loadSubScript (url, optionsObject)
+     * @param url the url of the sub-script, it MUST be either a file:,
+     *            resource:, or chrome: url, and MUST be local.
+     * @param optionsObject an object with parameters. Valid parameters are:
+     *                      - charset: specifying the character encoding of the file (default: ASCII)
+     *                      - target:  an object to evaluate onto (default: global object of the caller)
+     *                      - ignoreCache: if set to true, will bypass the cache for reading the file.
+     * @retval rv the value returned by the sub-script
+     */
+    [implicit_jscontext]
+    jsval loadSubScriptWithOptions(in AString url, in jsval options);
+
+    /*
+     * Compiles a JS script off the main thread and calls back the
+     * observer once it's done.
+     * The script will be cached in temporary or persistent storage depending
+     * on the principal used.
+     * We fire the notification callback in all cases - there is no fatal
+     * error there.
+     * @param uri       the uri of the script to load.
+     * @param principal the principal from which we get the app id if any.
+     * @param observer  this observer will be called once the script has
+     *                  been precompiled. The notification topic will be
+     *                  'script-precompiled' and the subject the uri of the
+     *                  script as a nsIURI.
+     */
+    void precompileScript(in nsIURI uri,
+                          in nsIPrincipal principal,
+                          in nsIObserver observer);
+};