Add constructors for WebAudio nodes

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

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 16 matching lines @@
     "HRTF"
 };
 
 enum DistanceModelType {
     "linear",
     "inverse",
     "exponential"
 };
 
 [
-    NoInterfaceObject,
+    Constructor(AudioContext context, optional PannerOptions options),
+    RaisesException=Constructor,
 ] interface PannerNode : AudioNode {
     // Default model for stereo is equalpower.
     attribute PanningModelType panningModel;
 
     // Uses a 3D cartesian coordinate system
     [MeasureAs=PannerNodeSetPosition] void setPosition(float x, float y, float z);
     [MeasureAs=PannerNodeSetOrientation] void setOrientation(float x, float y, float z);
     [DeprecateAs=PannerNodeSetVelocity] void setVelocity(float x, float y, float z);
 
     // Uses a 3D cartesian coordinate system
@@ skipping 10 matching lines @@
 
     attribute double refDistance;
     attribute double maxDistance;
     attribute double rolloffFactor;
 
     // Directional sound cone
     attribute double coneInnerAngle;
     attribute double coneOuterAngle;
     attribute double coneOuterGain;
 };