[presubmit] Enable readability/namespace linter checking.

src/frames-inl.h

 // Copyright 2012 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_FRAMES_INL_H_
 #define V8_FRAMES_INL_H_
 
 #include "src/frames.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
@@ skipping 268 matching lines @@
 }
 
 
 inline StackFrame* SafeStackFrameIterator::frame() const {
   DCHECK(!done());
   DCHECK(frame_->is_java_script() || frame_->is_exit());
   return frame_;
 }
 
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_FRAMES_INL_H_