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

components/search_engines/template_url_service.cc

Index: components/search_engines/template_url_service.cc
diff --git a/components/search_engines/template_url_service.cc b/components/search_engines/template_url_service.cc
index ee12247b7e05e9ee6eb700c5464e914503b57d10..56ec6a55ba74fbd2b7135b78aebca554a59c55fd 100644
--- a/components/search_engines/template_url_service.cc
+++ b/components/search_engines/template_url_service.cc
@@ -413,6 +413,10 @@ void TemplateURLService::AddMatchingDomainKeywords(
       matches);
 }
 
+bool TemplateURLService::IsInDefaultList(const TemplateURL* t_url) {
+  return t_url->prepopulate_id() > 0 || t_url->created_by_policy();
+}
+
 TemplateURL* TemplateURLService::GetTemplateURLForKeyword(
     const base::string16& keyword) {
   KeywordToTURLAndMeaningfulLength::const_iterator elem(
@@ -1642,7 +1646,7 @@ bool TemplateURLService::CanAddAutogeneratedKeywordForHost(
 }
 
 bool TemplateURLService::CanReplace(const TemplateURL* t_url) {
-  return (t_url != default_search_provider_ && !t_url->show_in_default_list() &&
+  return (t_url != default_search_provider_ && !IsInDefaultList(t_url) &&
           t_url->safe_for_autoreplace());
 }