diff -r 000000000000 -r 6474c204b198 dom/ipc/FileDescriptorSetChild.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/ipc/FileDescriptorSetChild.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: set sw=4 ts=8 et tw=80 : */
+/* 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 "mozilla/dom/FileDescriptorSetChild.h"
+
+namespace mozilla {
+namespace dom {
+
+FileDescriptorSetChild::FileDescriptorSetChild(
+                                         const FileDescriptor& aFileDescriptor)
+{
+  mFileDescriptors.AppendElement(aFileDescriptor);
+}
+
+FileDescriptorSetChild::~FileDescriptorSetChild()
+{
+  MOZ_ASSERT(mFileDescriptors.IsEmpty());
+}
+
+void
+FileDescriptorSetChild::ForgetFileDescriptors(
+                                    nsTArray<FileDescriptor>& aFileDescriptors)
+{
+  aFileDescriptors.Clear();
+  mFileDescriptors.SwapElements(aFileDescriptors);
+}
+
+bool
+FileDescriptorSetChild::RecvAddFileDescriptor(
+                                         const FileDescriptor& aFileDescriptor)
+{
+  mFileDescriptors.AppendElement(aFileDescriptor);
+  return true;
+}
+
+} // dom namespace
+} // mozilla namespace