Oilpan: A thread that is not attached to Oilpan shouldn't create a CrossThreadPersistent

Source/modules/webaudio/ScriptProcessorNode.cpp

Index: Source/modules/webaudio/ScriptProcessorNode.cpp
diff --git a/Source/modules/webaudio/ScriptProcessorNode.cpp b/Source/modules/webaudio/ScriptProcessorNode.cpp
index 696a1600d5acde95cbf05f7ef281f38752566e8e..76ba5a0f99727e5cc9184d8c5fb305cf41acc00f 100644
--- a/Source/modules/webaudio/ScriptProcessorNode.cpp
+++ b/Source/modules/webaudio/ScriptProcessorNode.cpp
@@ -38,6 +38,7 @@
 #include "modules/webaudio/AudioProcessingEvent.h"
 #include "public/platform/Platform.h"
 #include "wtf/Float32Array.h"
+#include "wtf/UnretainedPtr.h"
 
 namespace blink {
 
@@ -230,7 +231,7 @@ void ScriptProcessorNode::process(size_t framesToProcess)
         } else if (context()->executionContext()) {
             // Fire the event on the main thread, not this one (which is the realtime audio thread).
             m_doubleBufferIndexForEvent = m_doubleBufferIndex;
-            context()->executionContext()->postTask(createCrossThreadTask(&ScriptProcessorNode::fireProcessEvent, this));
+            context()->executionContext()->postTask(createCrossThreadTask(&ScriptProcessorNode::fireProcessEvent, UnretainedPtr<ScriptProcessorNode>(this)));
         }
 
         swapBuffers();