[presubmit] Enable readability/namespace linter checking.

src/allocation.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_ALLOCATION_H_
 #define V8_ALLOCATION_H_
 
 #include "src/globals.h"
 
 namespace v8 {
@@ skipping 70 matching lines @@
 class FreeStoreAllocationPolicy {
  public:
   INLINE(void* New(size_t size)) { return Malloced::New(size); }
   INLINE(static void Delete(void* p)) { Malloced::Delete(p); }
 };
 
 
 void* AlignedAlloc(size_t size, size_t alignment);
 void AlignedFree(void *ptr);
 
-} }  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_ALLOCATION_H_