[presubmit] Enable readability/namespace linter checking.

src/ast-expression-visitor.h

 // 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.
 
 #ifndef V8_AST_EXPRESSION_VISITOR_H_
 #define V8_AST_EXPRESSION_VISITOR_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/effects.h"
@@ skipping 25 matching lines @@
 
 #define DECLARE_VISIT(type) virtual void Visit##type(type* node) override;
   AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT
 
   FunctionLiteral* root_;
   int depth_;
 
   DISALLOW_COPY_AND_ASSIGN(AstExpressionVisitor);
 };
-}
-}  // namespace v8::internal
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_AST_EXPRESSION_VISITOR_H_