MediaRecorder: Adding BlobEvent and connecting it in MediaRecorderHandler

Source/modules/mediarecorder/BlobEvent.idl

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://w3c.github.io/mediacapture-record/MediaRecorder.html#blob-event
+
+[
+    // This constructor is not strictly part of the spec but is very useful, see
+    // https://github.com/w3c/mediacapture-record/issues/11

[Peter Beverloo, 2015/09/22 14:03:42]

It is, but the spec should be updated to properly define it. (Otherwise there is
no sense in defining BlobEventInit.)

What about the following TODO?

// The constructor is yet to be added to the specification, see:
// https://github.com/w3c/mediacapture-record/issues/11

[mcasas, 2015/09/22 16:18:48]

Done.

+    Constructor(DOMString type, optional BlobEventInit eventInit)

[Peter Beverloo, 2015/09/22 14:03:42]

RuntimeEnabled=MediaRecorder

[mcasas, 2015/09/22 16:18:48]

Done.

+]
+interface BlobEvent : Event {
+    readonly attribute Blob data;
+};