[presubmit] Enable readability/namespace linter checking.

src/cached-powers.h

 // Copyright 2010 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_CACHED_POWERS_H_
 #define V8_CACHED_POWERS_H_
 
 #include "src/base/logging.h"
 #include "src/diy-fp.h"
 
@@ skipping 19 matching lines @@
   // Returns a cached power of ten x ~= 10^k such that
   //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
   // The given decimal_exponent must satisfy
   //   kMinDecimalExponent <= requested_exponent, and
   //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
   static void GetCachedPowerForDecimalExponent(int requested_exponent,
                                                DiyFp* power,
                                                int* found_exponent);
 };
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_CACHED_POWERS_H_