diff -r 000000000000 -r 6474c204b198 gfx/layers/ipc/ShadowLayerParent.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/ipc/ShadowLayerParent.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,131 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 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 "ShadowLayerParent.h"
+#include "Layers.h"                     // for Layer, ContainerLayer
+#include "nsDebug.h"                    // for NS_RUNTIMEABORT
+#include "nsISupportsImpl.h"            // for Layer::AddRef, etc
+
+#include "mozilla/layers/ThebesLayerComposite.h"
+#include "mozilla/layers/CanvasLayerComposite.h"
+#include "mozilla/layers/ColorLayerComposite.h"
+#include "mozilla/layers/ImageLayerComposite.h"
+#include "mozilla/layers/ContainerLayerComposite.h"
+
+namespace mozilla {
+namespace layers {
+
+ShadowLayerParent::ShadowLayerParent() : mLayer(nullptr)
+{
+}
+
+ShadowLayerParent::~ShadowLayerParent()
+{
+}
+
+void
+ShadowLayerParent::Bind(Layer* layer)
+{
+  mLayer = layer;
+}
+
+void
+ShadowLayerParent::Destroy()
+{
+  // It's possible for Destroy() to come in just after this has been
+  // created, but just before the transaction in which Bind() would
+  // have been called.  In that case, we'll ignore shadow-layers
+  // transactions from there on and never get a layer here.
+  if (mLayer) {
+    mLayer->Disconnect();
+  }
+}
+
+ContainerLayerComposite*
+ShadowLayerParent::AsContainerLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_CONTAINER
+         ? static_cast<ContainerLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+CanvasLayerComposite*
+ShadowLayerParent::AsCanvasLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_CANVAS
+         ? static_cast<CanvasLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+ColorLayerComposite*
+ShadowLayerParent::AsColorLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_COLOR
+         ? static_cast<ColorLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+ImageLayerComposite*
+ShadowLayerParent::AsImageLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_IMAGE
+         ? static_cast<ImageLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+RefLayerComposite*
+ShadowLayerParent::AsRefLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_REF
+         ? static_cast<RefLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+ThebesLayerComposite*
+ShadowLayerParent::AsThebesLayerComposite() const
+{
+  return mLayer && mLayer->GetType() == Layer::TYPE_THEBES
+         ? static_cast<ThebesLayerComposite*>(mLayer.get())
+         : nullptr;
+}
+
+void
+ShadowLayerParent::ActorDestroy(ActorDestroyReason why)
+{
+  switch (why) {
+  case AncestorDeletion:
+    NS_RUNTIMEABORT("shadow layer deleted out of order!");
+    return;                     // unreached
+
+  case Deletion:
+    // See comment near Destroy() above.
+    if (mLayer) {
+      mLayer->Disconnect();
+    }
+    break;
+
+  case AbnormalShutdown:
+    if (mLayer) {
+      mLayer->Disconnect();
+    }
+    break;
+
+  case NormalShutdown:
+    // let IPDL-generated code automatically clean up Shmems and so
+    // forth; our channel is disconnected anyway
+    break;
+
+  case FailedConstructor:
+    NS_RUNTIMEABORT("FailedConstructor isn't possible in PLayerTransaction");
+    return;                     // unreached
+  }
+
+  mLayer = nullptr;
+}
+
+} // namespace layers
+} // namespace mozilla