Bug 1275856 - Add MediaRecorderErrorEvent webidl files and update moz.build. r=jib,smaug

This adds the webidl definition of the MediaRecorderErrorEvent given in the
spec. It also updates the build system to give us generated C++ code for this
event.

MozReview-Commit-ID: Bi1f0tD9iUj

--HG--
extra : rebase_source : 0cb10aab1a8a8fd7720c5d069cf4ac65817a9855

dom/webidl/MediaRecorderErrorEvent.webidl

@@ -0,0 +1,21 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/.
+ *
+ * The origin of this IDL file is
+ * https://w3c.github.io/mediacapture-record/
+ *
+ * Copyright © 2017 W3C® (MIT, ERCIM, Keio, Beihang). W3C liability, trademark
+ * and document use rules apply.
+ */
+
+dictionary MediaRecorderErrorEventInit : EventInit {
+  required DOMException error;
+};
+
+[Exposed=Window,
+  Constructor(DOMString type, MediaRecorderErrorEventInit eventInitDict)]
+interface MediaRecorderErrorEvent : Event {
+  [SameObject] readonly attribute DOMException error;
+};

dom/webidl/moz.build

@@ -1080,6 +1080,7 @@ GENERATED_EVENTS_WEBIDL_FILES = [
     'HiddenPluginEvent.webidl',
     'ImageCaptureErrorEvent.webidl',
     'MediaQueryListEvent.webidl',
+    'MediaRecorderErrorEvent.webidl',
     'MediaStreamEvent.webidl',
     'MediaStreamTrackEvent.webidl',
     'OfflineAudioCompletionEvent.webidl',