diff -r 000000000000 -r 6474c204b198 dom/plugins/ipc/PluginIdentifierParent.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/plugins/ipc/PluginIdentifierParent.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,89 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et :
+ * 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 dom_plugins_PluginIdentifierParent_h
+#define dom_plugins_PluginIdentifierParent_h
+
+#include "mozilla/plugins/PPluginIdentifierParent.h"
+
+#include "npapi.h"
+#include "npruntime.h"
+
+namespace mozilla {
+namespace plugins {
+
+class PluginInstanceParent;
+
+class PluginIdentifierParent : public PPluginIdentifierParent
+{
+  friend class PluginModuleParent;
+
+public:
+  NPIdentifier ToNPIdentifier()
+  {
+    return mIdentifier;
+  }
+
+  bool IsTemporary() {
+    return !!mTemporaryRefs;
+  }
+
+  /**
+   * Holds a perhaps-temporary identifier for the current stack frame.
+   */
+  class MOZ_STACK_CLASS StackIdentifier
+  {
+  public:
+    StackIdentifier(PluginInstanceParent* inst, NPIdentifier aIdentifier);
+    StackIdentifier(NPObject* aObject, NPIdentifier aIdentifier);
+    ~StackIdentifier();
+
+    operator PluginIdentifierParent*() {
+      return mIdentifier;
+    }
+
+  private:
+    DISALLOW_COPY_AND_ASSIGN(StackIdentifier);
+
+    PluginIdentifierParent* mIdentifier;
+  };
+
+protected:
+  PluginIdentifierParent(NPIdentifier aIdentifier, bool aTemporary)
+    : mIdentifier(aIdentifier)
+    , mTemporaryRefs(aTemporary ? 1 : 0)
+  {
+    MOZ_COUNT_CTOR(PluginIdentifierParent);
+  }
+
+  virtual ~PluginIdentifierParent()
+  {
+    MOZ_COUNT_DTOR(PluginIdentifierParent);
+  }
+
+  virtual bool RecvRetain() MOZ_OVERRIDE;
+
+  void AddTemporaryRef() {
+    mTemporaryRefs++;
+  }
+
+  /**
+   * @returns true if the last temporary reference was removed.
+   */
+  bool RemoveTemporaryRef() {
+    --mTemporaryRefs;
+    return !mTemporaryRefs;
+  }
+
+private:
+  NPIdentifier mIdentifier;
+  unsigned int mTemporaryRefs;
+};
+
+} // namespace plugins
+} // namespace mozilla
+
+#endif // dom_plugins_PluginIdentifierParent_h