[presubmit] Enable readability/namespace linter checking.

src/runtime/runtime-futex.cc

 // Copyright 2015 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.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/base/platform/time.h"
 #include "src/conversions-inl.h"
 #include "src/futex-emulation.h"
@@ skipping 71 matching lines @@
   CONVERT_SIZE_ARG_CHECKED(index, 1);
   RUNTIME_ASSERT(sta->GetBuffer()->is_shared());
   RUNTIME_ASSERT(index < NumberToSize(isolate, sta->length()));
   RUNTIME_ASSERT(sta->type() == kExternalInt32Array);
 
   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
   size_t addr = index << 2;
 
   return FutexEmulation::NumWaitersForTesting(isolate, array_buffer, addr);
 }
-}
-}  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8