[translate] Add translate ranker model loader.

components/translate/core/common/translate_switches.cc

 // Copyright 2014 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 "components/translate/core/common/translate_switches.h"
 
 namespace translate {
 namespace switches {
 
 // Allows disabling of translate from the command line to assist with automated
 // browser testing (e.g. Selenium/WebDriver). Normal browser users should
 // disable translate with the preference.
 const char kDisableTranslate[] = "disable-translate";
 
 // Overrides the default server used for Google Translate.
 const char kTranslateScriptURL[] = "translate-script-url";
 
 // Overrides security-origin with which Translate runs in an isolated world.
 const char kTranslateSecurityOrigin[] = "translate-security-origin";
 
 // Overrides the URL from which the translate ranker model is downloaded.
 const char kTranslateRankerModelURL[] = "translate-ranker-model-url";
 
+// Overrides the path in which the translate ranker model is cached.
+const char kTranslateRankerModelPath[] = "translate-ranker-model-path";
 }  // namespace switches
 }  // namespace translate