[presubmit] Enable readability/namespace linter checking.

src/transitions.h

 // Copyright 2012 the V8 project 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 V8_TRANSITIONS_H_
 #define V8_TRANSITIONS_H_
 
 #include "src/checks.h"
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
@@ skipping 284 matching lines @@
 #ifdef DEBUG
   static void CheckNewTransitionsAreConsistent(Handle<Map> map,
                                                TransitionArray* old_transitions,
                                                Object* transitions);
 #endif
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(TransitionArray);
 };
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_TRANSITIONS_H_