[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/nacl_io/mount_node_http.h

 /* Copyright (c) 2013 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_MOUNT_NODE_HTTP_H_
 #define LIBRARIES_NACL_IO_MOUNT_NODE_HTTP_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "nacl_io/error.h"
 #include "nacl_io/mount_node.h"
 #include "nacl_io/pepper_interface.h"
 
+namespace nacl_io {
+
 typedef std::map<std::string, std::string> StringMap_t;
 
 class MountNodeHttp : public MountNode {
  public:
   virtual Error FSync();
   virtual Error GetDents(size_t offs,
                          struct dirent* pdir,
                          size_t count,
                          int* out_bytes);
   virtual Error GetStat(struct stat* stat);
@@ skipping 33 matching lines @@
   std::string url_;
   std::vector<char> buffer_;
 
   bool cache_content_;
   bool has_cached_size_;
   std::vector<char> cached_data_;
 
   friend class MountHttp;
 };
 
+}  // namespace nacl_io
+
 #endif  // LIBRARIES_NACL_IO_MOUNT_NODE_HTTP_H_