Standardize usage of virtual/override/final in chrome/

chrome/common/extensions/api/speech/tts_engine_manifest_handler.cc

 // Copyright (c) 2012 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/speech/tts_engine_manifest_handler.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/manifest.h"
 #include "extensions/common/manifest_constants.h"
 #include "ui/base/l10n/l10n_util.h"
 
 namespace extensions {
 
 namespace keys = manifest_keys;
 namespace errors = manifest_errors;
 
 namespace {
 
 struct TtsVoices : public Extension::ManifestData {
   TtsVoices() {}
-  virtual ~TtsVoices() {}
+  ~TtsVoices() override {}
 
   std::vector<extensions::TtsVoice> voices;
 };
 
 }  // namespace
 
 TtsVoice::TtsVoice() : remote(false) {}
 
 TtsVoice::~TtsVoice() {}
 
@@ skipping 106 matching lines @@
 
   extension->SetManifestData(keys::kTtsVoices, info.release());
   return true;
 }
 
 const std::vector<std::string> TtsEngineManifestHandler::Keys() const {
   return SingleKey(keys::kTtsEngine);
 }
 
 }  // namespace extensions