Move the ScopedMinijail deleter to a named namespace.

Keeping it in an anonymous namespace was causing (very hard to
diagnose) breakage.

Bug: None
Test: Unit tests still pass.
Change-Id: Icaf4fdc3d83d38fb474002b50b765949fe1db6b2
diff --git a/scoped_minijail.h b/scoped_minijail.h
index 27bf487..38f1a91 100644
--- a/scoped_minijail.h
+++ b/scoped_minijail.h
@@ -10,7 +10,10 @@
 
 #include "libminijail.h"
 
-namespace {
+namespace mj {
+
+namespace internal {
+
 struct ScopedMinijailDeleter {
     inline void operator()(minijail *j) const {
         if (j) {
@@ -18,8 +21,12 @@
         }
     }
 };
-}
 
-using ScopedMinijail = std::unique_ptr<minijail, ScopedMinijailDeleter>;
+}   // namespace internal
+
+}   // namespace mj
+
+using ScopedMinijail =
+        std::unique_ptr<minijail, mj::internal::ScopedMinijailDeleter>;
 
 #endif /* _SCOPED_MINIJAIL_H_ */