Standardize usage of virtual/override/final in extensions/

extensions/browser/file_highlighter.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_BROWSER_FILE_HIGHLIGHTER_H_
 #define EXTENSIONS_BROWSER_FILE_HIGHLIGHTER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 55 matching lines @@
 // 'tabs' within 'permissions' would just be '"tabs"'.
 // We can't use the JSONParser to do this, because we want to display the actual
 // manifest, and once we parse it into Values, we lose any formatting the user
 // may have had.
 // If a feature cannot be found, the feature will have zero-length.
 class ManifestHighlighter : public FileHighlighter {
  public:
   ManifestHighlighter(const std::string& manifest,
                       const std::string& key,
                       const std::string& specific /* optional */);
-  virtual ~ManifestHighlighter();
+  ~ManifestHighlighter() override;
 
  private:
   // Called from the constructor; determine the start and end bounds of a
   // feature, using both the key and specific information.
   void Parse(const std::string& key, const std::string& specific);
 
   // Find the bounds of any feature, either a full key or a specific item within
   // the key. |enforce_at_top_level| means that the feature we find must be at
   // the same level as |start_| (i.e., ignore nested elements).
   // Returns true on success.
   bool FindBounds(const std::string& feature, bool enforce_at_top_level);
 
   // Finds the end of the feature.
   void FindBoundsEnd(const std::string& feature, size_t local_start);
 
   DISALLOW_COPY_AND_ASSIGN(ManifestHighlighter);
 };
 
 // Use the SourceHighlighter to highlight a particular line in a given source
 // file.
 class SourceHighlighter : public FileHighlighter {
  public:
   SourceHighlighter(const std::string& source, size_t line_number);
-  virtual ~SourceHighlighter();
+  ~SourceHighlighter() override;
 
  private:
   // Called from the constructor; determine the bounds of the line in the source
   // file.
   void Parse(size_t line_number);
 
   DISALLOW_COPY_AND_ASSIGN(SourceHighlighter);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_FILE_HIGHLIGHTER_H_