[presubmit] Enable readability/namespace linter checking.

src/strings-storage.h

 // Copyright 2015 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_STRINGS_STORAGE_H_
 #define V8_STRINGS_STORAGE_H_
 
 #include "src/allocation.h"
 #include "src/hashmap.h"
 
@@ skipping 23 matching lines @@
 
   static bool StringsMatch(void* key1, void* key2);
   const char* AddOrDisposeString(char* str, int len);
   HashMap::Entry* GetEntry(const char* str, int len);
 
   uint32_t hash_seed_;
   HashMap names_;
 
   DISALLOW_COPY_AND_ASSIGN(StringsStorage);
 };
-}
-}  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_STRINGS_STORAGE_H_