Made AudioNode an EventTarget

Source/modules/webaudio/AudioNode.cpp

Index: Source/modules/webaudio/AudioNode.cpp
diff --git a/Source/modules/webaudio/AudioNode.cpp b/Source/modules/webaudio/AudioNode.cpp
index 5972418a923bfd20152c9607d9d080047c6e3915..9426fed191a308bfac65d3442c816bdf77ac3f8e 100644
--- a/Source/modules/webaudio/AudioNode.cpp
+++ b/Source/modules/webaudio/AudioNode.cpp
@@ -283,10 +283,20 @@ void AudioNode::updateChannelsForInputs()
         input(i)->changedOutputs();
 }
 
+const AtomicString& AudioNode::interfaceName() const
+{
+    return eventNames().interfaceForAudioNode;
+}
+
+ScriptExecutionContext* AudioNode::scriptExecutionContext() const
+{
+    return const_cast<AudioNode*>(this)->context()->scriptExecutionContext();
+}
+
 void AudioNode::processIfNecessary(size_t framesToProcess)
 {
     ASSERT(context()->isAudioThread());
-    
+
     if (!isInitialized())
         return;