Add field to monitor last visited time for each search engine

components/search_engines/template_url_service.h

Index: components/search_engines/template_url_service.h
diff --git a/components/search_engines/template_url_service.h b/components/search_engines/template_url_service.h
index 4a8a5af3f6d10e7d484ffa77b6b7216b78a262f8..f46e594671c7d8cbe8379d3fbd77e115d7b31430 100644
--- a/components/search_engines/template_url_service.h
+++ b/components/search_engines/template_url_service.h
@@ -413,6 +413,7 @@ class TemplateURLService : public WebDataServiceConsumer,
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceTest, ChangeGoogleBaseValue);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceTest, MergeDeletesUnusedProviders);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceTest, AddExtensionKeyword);
+  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceTest, LastVisitedTimeUpdate);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest, UniquifyKeyword);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
                            IsLocalTemplateURLBetter);
@@ -547,6 +548,10 @@ class TemplateURLService : public WebDataServiceConsumer,
   bool UpdateNoNotify(TemplateURL* existing_turl,
                       const TemplateURL& new_values);
 
+  // Calls UpdateNoNotify() and NotifyObservers() if update succeeds.
+  // Returns the result of UpdateNoNotify().
+  bool Update(TemplateURL* existing_turl, const TemplateURL& new_values);
+
   // If the TemplateURL comes from a prepopulated URL available in the current
   // country, update all its fields save for the keyword, short name and id so
   // that they match the internal prepopulated URL. TemplateURLs not coming from
@@ -564,6 +569,9 @@ class TemplateURLService : public WebDataServiceConsumer,
   // SetKeywordSearchTermsForURL is invoked.
   void UpdateKeywordSearchTermsForURL(const URLVisitedDetails& details);
 
+  // Updates the last_visited time of TemplateURL to the current time.

[Peter Kasting, 2016/12/02 21:31:13]

Nit: TemplateURL -> |url|

+  void UpdateTemplateURLVisitTime(TemplateURL* url);
+
   // If necessary, generates a visit for the site http:// + t_url.keyword().
   void AddTabToSearchVisit(const TemplateURL& t_url);