diff -r 000000000000 -r 6474c204b198 content/media/webaudio/PlayingRefChangeHandler.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/webaudio/PlayingRefChangeHandler.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,56 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef PlayingRefChangeHandler_h__
+#define PlayingRefChangeHandler_h__
+
+#include "nsThreadUtils.h"
+#include "AudioNodeStream.h"
+
+namespace mozilla {
+namespace dom {
+
+class PlayingRefChangeHandler : public nsRunnable
+{
+public:
+  enum ChangeType { ADDREF, RELEASE };
+  PlayingRefChangeHandler(AudioNodeStream* aStream, ChangeType aChange)
+    : mStream(aStream)
+    , mChange(aChange)
+  {
+  }
+
+  NS_IMETHOD Run()
+  {
+    nsRefPtr<AudioNode> node;
+    {
+      // No need to keep holding the lock for the whole duration of this
+      // function, since we're holding a strong reference to it, so if
+      // we can obtain the reference, we will hold the node alive in
+      // this function.
+      MutexAutoLock lock(mStream->Engine()->NodeMutex());
+      node = mStream->Engine()->Node();
+    }
+    if (node) {
+      if (mChange == ADDREF) {
+        node->MarkActive();
+      } else if (mChange == RELEASE) {
+        node->MarkInactive();
+      }
+    }
+    return NS_OK;
+  }
+
+private:
+  nsRefPtr<AudioNodeStream> mStream;
+  ChangeType mChange;
+};
+
+}
+}
+
+#endif
+