Implement StereoPannerNode for robust stereo panning

Source/modules/webaudio/AudioNode.cpp

 /*
  * 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 108 matching lines @@
     case NodeTypeMediaStreamAudioDestination:
         return "MediaStreamAudioDestinationNode";
     case NodeTypeMediaStreamAudioSource:
         return "MediaStreamAudioSourceNode";
     case NodeTypeJavaScript:
         return "ScriptProcessorNode";
     case NodeTypeBiquadFilter:
         return "BiquadFilterNode";
     case NodeTypePanner:
         return "PannerNode";
+    case NodeTypeStereoPanner:
+        return "StereoPannerNode";
     case NodeTypeConvolver:
         return "ConvolverNode";
     case NodeTypeDelay:
         return "DelayNode";
     case NodeTypeGain:
         return "GainNode";
     case NodeTypeChannelSplitter:
         return "ChannelSplitterNode";
     case NodeTypeChannelMerger:
         return "ChannelMergerNode";
@@ skipping 429 matching lines @@
 
 void AudioNode::updateChannelCountMode()
 {
     m_channelCountMode = m_newChannelCountMode;
     updateChannelsForInputs();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)