Bug 876029 - Add Missing MPL header. r=jlebar DONTBUILD

xpcom/threads/nsMemoryPressure.cpp

@@ -1,3 +1,9 @@
+/* -*- 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/. */
+
 #include "nsMemoryPressure.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/Atomics.h"