[presubmit] Enable readability/namespace linter checking.

test/cctest/compiler/function-tester.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_CCTEST_COMPILER_FUNCTION_TESTER_H_
 #define V8_CCTEST_COMPILER_FUNCTION_TESTER_H_
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
@@ skipping 194 matching lines @@
                        Handle<Code>(function->shared()->code()));
     CHECK(Compiler::Analyze(info.parse_info()));
     CHECK(Compiler::EnsureDeoptimizationSupport(&info));
 
     Handle<Code> code = Pipeline::GenerateCodeForTesting(&info, graph);
     CHECK(!code.is_null());
     function->ReplaceCode(*code);
     return function;
   }
 };
-}
-}
-}  // namespace v8::internal::compiler
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
 
 #endif  // V8_CCTEST_COMPILER_FUNCTION_TESTER_H_