Remove the "Settings" packaged app

chrome/common/extensions/extension_constants.h

 // 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 76 matching lines @@
 
 // The extension id of the hotword audio verification dialogue app.
 extern const char kHotwordAudioVerificationAppId[];
 
 // The extension id of the new (experimental) hotword extension.
 extern const char kHotwordNewExtensionId[];
 
 // The extension id of the hotword shared module.
 extern const char kHotwordSharedModuleId[];
 
-// The extension id of the settings application.
-extern const char kSettingsAppId[];
-
 // The extension id of the Youtube application.
 extern const char kYoutubeAppId[];
 
 // The extension id of the in-app payments support application.
 extern const char kInAppPaymentsSupportAppId[];
 
 #if defined(ENABLE_MEDIA_ROUTER)
 // The extension id of the stable media router extension.
 extern const char kMediaRouterStableExtensionId[];
 #endif  // defined(ENABLE_MEDIA_ROUTER)
@@ skipping 144 matching lines @@
 extern const int kWebstoreSignaturesPublicKeySize;
 
 #if defined(OS_CHROMEOS)
 // Returns true if |extension_id| is one of the IME extensions that will create
 // IME menu.
 bool IsImeMenuExtensionId(const std::string& extension_id);
 #endif
 }  // namespace extension_misc
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_