Move webaudio to oilpan

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 f26bccb49dbe51a2893bbe7dea1c4046041354c4..dd929144588ccca41b2afeb5f26c476c5ce50815 100644
--- a/Source/modules/webaudio/AudioNode.cpp
+++ b/Source/modules/webaudio/AudioNode.cpp
@@ -48,6 +48,9 @@ AudioNode::AudioNode(AudioContext* context, float sampleRate)
     , m_nodeType(NodeTypeUnknown)
     , m_context(context)
     , m_sampleRate(sampleRate)
+#if ENABLE(OILPAN)
+    , m_keepAlive(adoptPtr(new Persistent<AudioNode>(this)))
+#endif
     , m_lastProcessingTime(-1)
     , m_lastNonSilentTime(-1)
     , m_normalRefCount(1) // start out with normal refCount == 1 (like WTF::RefCounted class)
@@ -586,6 +589,19 @@ void AudioNode::printNodeCounts()
 
 #endif // DEBUG_AUDIONODE_REFERENCES
 
+void AudioNode::trace(Visitor* visitor)
+{
+    visitor->trace(m_context);
+}
+
+#if ENABLE(OILPAN)
+void AudioNode::clearKeepAlive()
+{
+    ASSERT(m_keepAlive);
+    m_keepAlive = nullptr;
+}
+#endif
+
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)