[Android] Allow setting recently visited search engines as default search engine

chrome/browser/search_engines/template_url_service_android.h

Index: chrome/browser/search_engines/template_url_service_android.h
diff --git a/chrome/browser/search_engines/template_url_service_android.h b/chrome/browser/search_engines/template_url_service_android.h
index af5f38c08a212727731e298448ae5df747711b74..c714dd32888fdfc3e441761cccbebae6db1a1c9f 100644
--- a/chrome/browser/search_engines/template_url_service_android.h
+++ b/chrome/browser/search_engines/template_url_service_android.h
@@ -27,7 +27,7 @@ class TemplateUrlServiceAndroid : public TemplateURLServiceObserver {
   void SetUserSelectedDefaultSearchProvider(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
-      jint selected_index);
+      const base::android::JavaParamRef<jstring>& jkeyword);
   jint GetDefaultSearchProvider(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj);
@@ -71,13 +71,15 @@ class TemplateUrlServiceAndroid : public TemplateURLServiceObserver {
   base::android::ScopedJavaLocalRef<jstring> GetSearchEngineUrlFromTemplateUrl(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
-      jint index);
+      const base::android::JavaParamRef<jstring>& jkeyword);
 
   static bool Register(JNIEnv* env);
 
  private:
   ~TemplateUrlServiceAndroid() override;
 
+  bool IsInDefaultList(TemplateURL* url);
+
   bool IsPrepopulatedTemplate(TemplateURL* url);
 
   void OnTemplateURLServiceLoaded();
@@ -93,6 +95,8 @@ class TemplateUrlServiceAndroid : public TemplateURLServiceObserver {
   std::unique_ptr<TemplateURLService::Subscription> template_url_subscription_;
 
   DISALLOW_COPY_AND_ASSIGN(TemplateUrlServiceAndroid);
+
+  std::vector<TemplateURL*> template_url_list_;
 };
 
 #endif  // CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_ANDROID_H_