Standardize usage of virtual/override/final in chrome/

chrome/common/extensions/api/file_browser_handlers/file_browser_handler.cc

 // 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.
 
 #include "chrome/common/extensions/api/file_browser_handlers/file_browser_handler.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 28 matching lines @@
   if (access_str == kCreateAccessString)
     return kCreatePermission;
   return kInvalidPermission;
 }
 
 // Stored on the Extension.
 struct FileBrowserHandlerInfo : public extensions::Extension::ManifestData {
   FileBrowserHandler::List file_browser_handlers;
 
   FileBrowserHandlerInfo();
-  virtual ~FileBrowserHandlerInfo();
+  ~FileBrowserHandlerInfo() override;
 };
 
 FileBrowserHandlerInfo::FileBrowserHandlerInfo() {
 }
 
 FileBrowserHandlerInfo::~FileBrowserHandlerInfo() {
 }
 
 }  // namespace
 
@@ skipping 222 matching lines @@
     return false;  // Failed to parse file browser actions definition.
   }
 
   extension->SetManifestData(keys::kFileBrowserHandlers, info.release());
   return true;
 }
 
 const std::vector<std::string> FileBrowserHandlerParser::Keys() const {
   return SingleKey(keys::kFileBrowserHandlers);
 }