[presubmit] Enable readability/namespace linter checking.

src/profiler/heap-snapshot-generator.h

 // Copyright 2013 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_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_
 #define V8_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_
 
 #include "include/v8-profiler.h"
 #include "src/base/platform/time.h"
 #include "src/objects.h"
@@ skipping 598 matching lines @@
   int next_string_id_;
   OutputStreamWriter* writer_;
 
   friend class HeapSnapshotJSONSerializerEnumerator;
   friend class HeapSnapshotJSONSerializerIterator;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshotJSONSerializer);
 };
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_