[presubmit] Enable readability/namespace linter checking.

src/hydrogen-osr.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_OSR_H_
 #define V8_HYDROGEN_OSR_H_
 
 #include "src/hydrogen.h"
 #include "src/ast.h"
 #include "src/zone.h"
@@ skipping 31 matching lines @@
   bool HasOsrEntryAt(IterationStatement* statement);
 
  private:
   int unoptimized_frame_slots_;
   HOptimizedGraphBuilder* builder_;
   HBasicBlock* osr_entry_;
   HBasicBlock* osr_loop_entry_;
   ZoneList<HUnknownOSRValue*>* osr_values_;
 };
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_HYDROGEN_OSR_H_