[presubmit] Enable readability/namespace linter checking.

src/profiler/sampler.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_SAMPLER_H_
 #define V8_PROFILER_SAMPLER_H_
 
 #include "include/v8.h"
 
 #include "src/base/atomicops.h"
@@ skipping 112 matching lines @@
   base::Atomic32 has_processing_thread_;
   base::Atomic32 active_;
   PlatformData* data_;  // Platform specific data.
   bool is_counting_samples_;
   // Counts stack samples taken in JS VM state.
   unsigned js_and_external_sample_count_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_PROFILER_SAMPLER_H_