Standardize usage of virtual/override/final in extensions/

extensions/common/manifest_handlers/csp_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_CSP_INFO_H_
 #define EXTENSIONS_COMMON_MANIFEST_HANDLERS_CSP_INFO_H_
 
 #include <string>
 
 #include "extensions/common/extension.h"
 #include "extensions/common/manifest_handler.h"
 
 namespace extensions {
 
 // A structure to hold the Content-Security-Policy information.
 struct CSPInfo : public Extension::ManifestData {
   explicit CSPInfo(const std::string& security_policy);
-  virtual ~CSPInfo();
+  ~CSPInfo() override;
 
   // The Content-Security-Policy for an extension.  Extensions can use
   // Content-Security-Policies to mitigate cross-site scripting and other
   // vulnerabilities.
   std::string content_security_policy;
 
   static const std::string& GetContentSecurityPolicy(
       const Extension* extension);
 
   // Returns the Content Security Policy that the specified resource should be
   // served with.
   static const std::string& GetResourceContentSecurityPolicy(
       const Extension* extension,
       const std::string& relative_path);
 };
 
 // Parses "content_security_policy" and "app.content_security_policy" keys.
 class CSPHandler : public ManifestHandler {
  public:
   explicit CSPHandler(bool is_platform_app);
-  virtual ~CSPHandler();
+  ~CSPHandler() override;
 
-  virtual bool Parse(Extension* extension, base::string16* error) override;
-  virtual bool AlwaysParseForType(Manifest::Type type) const override;
+  bool Parse(Extension* extension, base::string16* error) override;
+  bool AlwaysParseForType(Manifest::Type type) const override;
 
  private:
-  virtual const std::vector<std::string> Keys() const override;
+  const std::vector<std::string> Keys() const override;
 
   bool is_platform_app_;
 
   DISALLOW_COPY_AND_ASSIGN(CSPHandler);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_MANIFEST_HANDLERS_CSP_INFO_H_