Standardize usage of virtual/override/final in extensions/

extensions/renderer/logging_native_handler.h

 // Copyright 2014 The Chromium 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 EXTENSIONS_RENDERER_LOGGING_NATIVE_HANDLER_H_
 #define EXTENSIONS_RENDERER_LOGGING_NATIVE_HANDLER_H_
 
 #include <string>
 
 #include "extensions/renderer/object_backed_native_handler.h"
 
 namespace extensions {
 class ScriptContext;
 
 // Exposes logging.h macros to JavaScript bindings.
 class LoggingNativeHandler : public ObjectBackedNativeHandler {
  public:
   explicit LoggingNativeHandler(ScriptContext* context);
-  virtual ~LoggingNativeHandler();
+  ~LoggingNativeHandler() override;
 
   // Equivalent to CHECK(predicate) << message.
   //
   // void(predicate, message?)
   void Check(const v8::FunctionCallbackInfo<v8::Value>& args);
 
   // Equivalent to DCHECK(predicate) << message.
   //
   // void(predicate, message?)
   void Dcheck(const v8::FunctionCallbackInfo<v8::Value>& args);
@@ skipping 17 matching lines @@
                  bool* check_value,
                  std::string* error_message);
 
   std::string ToStringOrDefault(const v8::Handle<v8::String>& v8_string,
                                 const std::string& dflt);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_LOGGING_NATIVE_HANDLER_H_