Standardize usage of virtual/override/final in extensions/

extensions/common/manifest_handlers/webview_info.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_COMMON_MANIFEST_HANDLERS_WEBVIEW_INFO_H_
 #define EXTENSIONS_COMMON_MANIFEST_HANDLERS_WEBVIEW_INFO_H_
 
 #include <string>
 
 #include "base/memory/scoped_vector.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_handler.h"
 
 namespace extensions {
 
 class PartitionItem;
 
 // A class to hold the <webview> accessible extension resources
 // that may be specified in the manifest of an extension using the
 // "webview" key.
 class WebviewInfo : public Extension::ManifestData {
  public:
   // Define out of line constructor/destructor to please Clang.
   WebviewInfo();
-  virtual ~WebviewInfo();
+  ~WebviewInfo() override;
 
   // Returns true if the specified resource is web accessible.
   static bool IsResourceWebviewAccessible(const Extension* extension,
                                           const std::string& partition_id,
                                           const std::string& relative_path);
 
   void AddPartitionItem(scoped_ptr<PartitionItem> item);
 
  private:
   ScopedVector<PartitionItem> partition_items_;
 };
 
 // Parses the "webview" manifest key.
 class WebviewHandler : public ManifestHandler {
  public:
   WebviewHandler();
-  virtual ~WebviewHandler();
+  ~WebviewHandler() override;
 
-  virtual bool Parse(Extension* extension, base::string16* error) override;
+  bool Parse(Extension* extension, base::string16* error) override;
 
  private:
-  virtual const std::vector<std::string> Keys() const override;
+  const std::vector<std::string> Keys() const override;
 
   DISALLOW_COPY_AND_ASSIGN(WebviewHandler);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_MANIFEST_HANDLERS_WEBVIEW_INFO_H_