Add field to monitor last visited time for each search engine

components/search_engines/template_url_data.h

Index: components/search_engines/template_url_data.h
diff --git a/components/search_engines/template_url_data.h b/components/search_engines/template_url_data.h
index 8036bc77729a658b9d097ad56b7ae46a520ef425..8df636229a32ae09c0383c5dd24240349e5f5333 100644
--- a/components/search_engines/template_url_data.h
+++ b/components/search_engines/template_url_data.h
@@ -82,6 +82,11 @@ struct TemplateURLData {
   // NOTE: Like date_created above, this may be 0.
   base::Time last_modified;
 
+  // Date when this TemplateURL was last visited.
+  //
+  // NOTE: Like data_created above, this may be 0.

[Peter Kasting, 2016/11/21 03:35:08]

Nit: I'd change this to "NOTE: This may be 0 if the URL has never been visited."

See also comment in .cc file.

[ltian, 2016/11/28 22:08:02]

Done.

+  base::Time last_visited;
+
   // True if this TemplateURL was automatically created by the administrator via
   // group policy.
   bool created_by_policy;