Standardize usage of virtual/override/final in extensions/

extensions/common/manifest_handlers/sandboxed_page_info.h

 // Copyright 2013 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_SANDBOXED_PAGE_INFO_H_
 #define EXTENSIONS_COMMON_MANIFEST_HANDLERS_SANDBOXED_PAGE_INFO_H_
 
 #include <string>
 
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_handler.h"
 #include "extensions/common/url_pattern_set.h"
 
 namespace extensions {
 
 struct SandboxedPageInfo : public Extension::ManifestData {
  public:
   SandboxedPageInfo();
-  virtual ~SandboxedPageInfo();
+  ~SandboxedPageInfo() override;
 
   // Returns the extension's Content Security Policy for the sandboxed pages.
   static const std::string& GetContentSecurityPolicy(
       const Extension* extension);
 
   // Returns the extension's sandboxed pages.
   static const URLPatternSet& GetPages(const Extension* extension);
 
   // Returns true if the specified page is sandboxed.
   static bool IsSandboxedPage(const Extension* extension,
                               const std::string& relative_path);
 
   // Optional list of extension pages that are sandboxed (served from a unique
   // origin with a different Content Security Policy).
   URLPatternSet pages;
 
   // Content Security Policy that should be used to enforce the sandbox used
   // by sandboxed pages (guaranteed to have the "sandbox" directive without the
   // "allow-same-origin" token).
   std::string content_security_policy;
 };
 
 class SandboxedPageHandler : public ManifestHandler {
  public:
   SandboxedPageHandler();
-  virtual ~SandboxedPageHandler();
+  ~SandboxedPageHandler() 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;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_MANIFEST_HANDLERS_SANDBOXED_PAGE_INFO_H_