diff -r 000000000000 -r 6474c204b198 dom/plugins/ipc/PluginBackgroundDestroyer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/plugins/ipc/PluginBackgroundDestroyer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: sw=4 ts=8 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/. */
+
+#include "PluginBackgroundDestroyer.h"
+#include "gfxSharedImageSurface.h"
+
+using namespace mozilla;
+using namespace plugins;
+
+PluginBackgroundDestroyerParent::PluginBackgroundDestroyerParent(gfxASurface* aDyingBackground)
+  : mDyingBackground(aDyingBackground)
+{
+}
+
+PluginBackgroundDestroyerParent::~PluginBackgroundDestroyerParent()
+{
+}
+
+void
+PluginBackgroundDestroyerParent::ActorDestroy(ActorDestroyReason why)
+{
+    switch(why) {
+    case Deletion:
+    case AncestorDeletion:
+        if (gfxSharedImageSurface::IsSharedImage(mDyingBackground)) {
+            gfxSharedImageSurface* s =
+                static_cast<gfxSharedImageSurface*>(mDyingBackground.get());
+            DeallocShmem(s->GetShmem());
+        }
+        break;
+    default:
+        // We're shutting down or crashed, let automatic cleanup
+        // take care of our shmem, if we have one.
+        break;
+    }
+}