Tried to move AudioSummingJuction to oilpan

Source/modules/webaudio/GainNode.cpp

Index: Source/modules/webaudio/GainNode.cpp
diff --git a/Source/modules/webaudio/GainNode.cpp b/Source/modules/webaudio/GainNode.cpp
index 08b2548a4317db216734ac3114a22e06e1264f78..265d8ce68f03bba4e12097c7e8b510072c7ddd37 100644
--- a/Source/modules/webaudio/GainNode.cpp
+++ b/Source/modules/webaudio/GainNode.cpp
@@ -42,7 +42,7 @@ GainNode::GainNode(AudioContext* context, float sampleRate)
     ScriptWrappable::init(this);
     m_gain = AudioParam::create(context, "gain", 1.0, 0.0, 1.0);
 
-    addInput(adoptPtr(new AudioNodeInput(this)));
+    addInput(adoptPtrWillBeNoop(new AudioNodeInput(this)));
     addOutput(adoptPtr(new AudioNodeOutput(this, 1)));
 
     setNodeType(NodeTypeGain);
@@ -108,6 +108,12 @@ void GainNode::checkNumberOfChannelsForInput(AudioNodeInput* input)
     AudioNode::checkNumberOfChannelsForInput(input);
 }
 
+void GainNode::trace(Visitor* visitor)
+{
+    visitor->trace(m_gain);
+    AudioNode::trace(visitor);
+}
+
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)