[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/nacl_io/path.h

 /* 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.
  */
 #ifndef LIBRARIES_NACL_IO_PATH_H_
 #define LIBRARIES_NACL_IO_PATH_H_
 
 #include <string>
 #include <vector>
 
 #include "sdk_util/macros.h"
 
+namespace nacl_io {
+
 typedef std::vector<std::string> StringArray_t;
 
 class Path {
  public:
   Path();
   Path(const Path& path);
 
   // This constructor splits path by '/' as a starting point for this Path.
   // If the path begins with the character '/', the path is considered
   // to be absolute.
@@ skipping 36 matching lines @@
   Path& operator=(const Path& p);
   Path& operator=(const std::string& str);
 
  private:
   // Internal representation of the path stored an array of string representing
   // the directory traversal.  The first string is a "/" if this is an absolute
   // path.
   StringArray_t paths_;
 };
 
+}  // namespace nacl_io
+
 #endif  // PACKAGES_LIBRARIES_NACL_IO_PATH_H_