[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/nacl_io/mount_html5fs.h

Index: native_client_sdk/src/libraries/nacl_io/mount_html5fs.h
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_html5fs.h b/native_client_sdk/src/libraries/nacl_io/mount_html5fs.h
index ff104bdbafb2bb23a098b95aa1f159b31daf7f5a..3aa2c2949977b74959096dc0f0523a6e38255e41 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_html5fs.h
+++ b/native_client_sdk/src/libraries/nacl_io/mount_html5fs.h
@@ -12,6 +12,8 @@
 #include "nacl_io/typed_mount_factory.h"
 #include "sdk_util/simple_lock.h"
 
+namespace nacl_io {
+
 class MountNode;
 
 class MountHtml5Fs : public Mount {
@@ -42,9 +44,11 @@ class MountHtml5Fs : public Mount {
   Error filesystem_open_error_;      // protected by lock_.
 
   pthread_cond_t filesystem_open_cond_;
-  SimpleLock filesysem_open_lock_;
+  sdk_util::SimpleLock filesysem_open_lock_;
 
   friend class TypedMountFactory<MountHtml5Fs>;
 };
 
+}  // namespace nacl_io
+
 #endif  // LIBRARIES_NACL_IO_MOUNT_HTML5FS_H_