[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/nacl_io/mount_mem.cc

Index: native_client_sdk/src/libraries/nacl_io/mount_mem.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_mem.cc b/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
index 41e0fddef998e2634f2aa87b9cffd55ec957fa22..141101d552869c23950313b85c7979c588fce28e 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
+++ b/native_client_sdk/src/libraries/nacl_io/mount_mem.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2012 The hromium Authors. All rights reserved.
+/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
@@ -19,6 +19,8 @@
 #include "sdk_util/auto_lock.h"
 #include "sdk_util/ref_object.h"
 
+namespace nacl_io {
+
 MountMem::MountMem() : root_(NULL) {}
 
 Error MountMem::Init(int dev, StringMap_t& args, PepperInterface* ppapi) {
@@ -221,3 +223,5 @@ Error MountMem::RemoveInternal(const Path& path, int remove_type) {
   return parent->RemoveChild(path.Basename());
 }
 
+}  // namespace nacl_io
+