Implement search engine auto switch when entering or leaving some locale

chrome/browser/android/locale/special_locale_handler.h

 // Copyright (c) 2016 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_BROWSER_ANDROID_LOCALE_SPECIAL_LOCALE_HANDLER_H_
 #define CHROME_BROWSER_ANDROID_LOCALE_SPECIAL_LOCALE_HANDLER_H_
 
 #include <jni.h>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
 #include "components/search_engines/template_url.h"
 
 using base::android::JavaParamRef;
 
 class TemplateURLService;
 
 class SpecialLocaleHandler {
  public:
   explicit SpecialLocaleHandler(const std::string& locale);
   void Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj);
   jboolean LoadTemplateUrls(JNIEnv* env, const JavaParamRef<jobject>& obj);
   void RemoveTemplateUrls(JNIEnv* env, const JavaParamRef<jobject>& obj);
   void OverrideDefaultSearchProvider(JNIEnv* env,
                                      const JavaParamRef<jobject>& obj);
+  void SetGoogleAsDefaultSearch(JNIEnv* env, const JavaParamRef<jobject>& obj);
 
  private:
   virtual ~SpecialLocaleHandler();
 
   std::string locale_;
 
   // Tracks all local search engines that were added to TURL service.
   std::vector<int> prepopulate_ids_;
 
   // Pointer to the TemplateUrlService for the main profile.
   TemplateURLService* template_url_service_;
 
   DISALLOW_COPY_AND_ASSIGN(SpecialLocaleHandler);
 };
 
 bool RegisterSpecialLocaleHandler(JNIEnv* env);
 
 #endif  // CHROME_BROWSER_ANDROID_LOCALE_SPECIAL_LOCALE_HANDLER_H_