[presubmit] Enable readability/namespace linter checking.

src/hydrogen-bce.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_HYDROGEN_BCE_H_
 #define V8_HYDROGEN_BCE_H_
 
 #include "src/hydrogen.h"
 
 namespace v8 {
@@ skipping 28 matching lines @@
   void EliminateRedundantBoundsChecks(HBasicBlock* bb);
   BoundsCheckBbData* PreProcessBlock(HBasicBlock* bb);
   void PostProcessBlock(HBasicBlock* bb, BoundsCheckBbData* data);
 
   BoundsCheckTable table_;
 
   DISALLOW_COPY_AND_ASSIGN(HBoundsCheckEliminationPhase);
 };
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_HYDROGEN_BCE_H_