Add constructors for WebAudio nodes

third_party/WebKit/Source/modules/webaudio/BaseAudioContext.idl

 // Copyright 2016 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.
 
-// WebAudio spec: https://webaudio.github.io/web-audio-api/#BaseAudioContext
+// See https://webaudio.github.io/web-audio-api/#BaseAudioContext
 enum AudioContextState {
     "suspended",
     "running",
     "closed"
 };
 
 [
     ActiveScriptWrappable,
     DependentLifetime,
     NoInterfaceObject,
@@ skipping 48 matching lines @@
     [MeasureAs=AudioContextResume, CallWith=ScriptState, ImplementedAs=resumeContext] Promise<void> resume();
 
     // TODO(rtoy): These really belong to the AudioContext, but we need them
     // here so we can use an offline audio context to test these.
     [RaisesException, MeasureAs=AudioContextCreateMediaElementSource] MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamSource] MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamDestination] MediaStreamAudioDestinationNode createMediaStreamDestination();
 
     attribute EventHandler onstatechange;
 };