Signal exceptions if start/stop is called out-of-order or too many times.

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 68 matching lines @@
 void AudioNode::initialize()
 {
     m_isInitialized = true;
 }
 
 void AudioNode::uninitialize()
 {
     m_isInitialized = false;
 }
 
+String AudioNode::nodeTypeName() const
+{
+    switch (m_nodeType) {
+    case NodeTypeDestination:
+        return "AudioDestinationNode";
+    case NodeTypeOscillator:
+        return "OscillatorNode";
+    case NodeTypeAudioBufferSource:
+        return "AudioBufferSourceNode";
+    case NodeTypeMediaElementAudioSource:
+        return "MediaElementAudioSourceNode";
+    case NodeTypeMediaStreamAudioDestination:
+        return "MediaStreamAudioDestinationNode";
+    case NodeTypeMediaStreamAudioSource:
+        return "MediaStreamAudioSourceNode";
+    case NodeTypeJavaScript:
+        return "ScriptProcessorNode";
+    case NodeTypeBiquadFilter:
+        return "BiquadFilterNode";
+    case NodeTypePanner:
+        return "PannerNode";
+    case NodeTypeConvolver:
+        return "ConvolverNode";
+    case NodeTypeDelay:
+        return "DelayNode";
+    case NodeTypeGain:
+        return "GainNode";
+    case NodeTypeChannelSplitter:
+        return "ChannelSplitterNode";
+    case NodeTypeChannelMerger:
+        return "ChannelMergerNode";
+    case NodeTypeAnalyser:
+        return "AnalyserNode";
+    case NodeTypeDynamicsCompressor:
+        return "DynamicsCompressorNode";
+    case NodeTypeWaveShaper:
+        return "WaveShaperNode";
+    case NodeTypeUnknown:
+    case NodeTypeEnd:
+    default:
+        ASSERT_NOT_REACHED();
+        return "UnknownNode";
+    }
+}
+
 void AudioNode::setNodeType(NodeType type)
 {
     m_nodeType = type;
 
 #if DEBUG_AUDIONODE_REFERENCES
     ++s_nodeCount[type];
 #endif
 }
 
 void AudioNode::lazyInitialize()
@@ skipping 480 matching lines @@
         fprintf(stderr, "%d: %d\n", i, s_nodeCount[i]);
 
     fprintf(stderr, "===========================\n\n\n");
 }
 
 #endif // DEBUG_AUDIONODE_REFERENCES
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)