[presubmit] Enable readability/namespace linter checking.

src/background-parsing-task.h

 // Copyright 2014 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_BACKGROUND_PARSING_TASK_H_
 #define V8_BACKGROUND_PARSING_TASK_H_
 
 #include "src/base/platform/platform.h"
 #include "src/base/platform/semaphore.h"
 #include "src/base/smart-pointers.h"
@@ skipping 36 matching lines @@
   BackgroundParsingTask(StreamedSource* source,
                         ScriptCompiler::CompileOptions options, int stack_size,
                         Isolate* isolate);
 
   virtual void Run();
 
  private:
   StreamedSource* source_;  // Not owned.
   int stack_size_;
 };
-}
-}  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_BACKGROUND_PARSING_TASK_H_