Add field to monitor last visited time for each search engine

components/search_engines/default_search_manager.cc

Index: components/search_engines/default_search_manager.cc
diff --git a/components/search_engines/default_search_manager.cc b/components/search_engines/default_search_manager.cc
index f30c0ff880289730afc1372c0b1e840943bb2527..d71f96c34320da93713603cffdab4f35798bdca0 100644
--- a/components/search_engines/default_search_manager.cc
+++ b/components/search_engines/default_search_manager.cc
@@ -67,6 +67,7 @@ const char DefaultSearchManager::kInputEncodings[] = "input_encodings";
 
 const char DefaultSearchManager::kDateCreated[] = "date_created";
 const char DefaultSearchManager::kLastModified[] = "last_modified";
+const char DefaultSearchManager::kLastVisited[] = "last_visited";
 
 const char DefaultSearchManager::kUsageCount[] = "usage_count";
 const char DefaultSearchManager::kAlternateURLs[] = "alternate_urls";
@@ -186,6 +187,8 @@ void DefaultSearchManager::SetUserSelectedDefaultSearchEngine(
                      base::Int64ToString(data.date_created.ToInternalValue()));
   url_dict.SetString(kLastModified,
                      base::Int64ToString(data.last_modified.ToInternalValue()));
+  url_dict.SetString(kLastVisited,
+                     base::Int64ToString(data.last_visited.ToInternalValue()));
   url_dict.SetInteger(kUsageCount, data.usage_count);
 
   std::unique_ptr<base::ListValue> alternate_urls(new base::ListValue);
@@ -279,6 +282,7 @@ void DefaultSearchManager::MergePrefsDataWithPrepopulated() {
     engine->sync_guid = prefs_default_search_->sync_guid;
     engine->date_created = prefs_default_search_->date_created;
     engine->last_modified = prefs_default_search_->last_modified;
+    engine->last_visited = prefs_default_search_->last_visited;
 
     prefs_default_search_ = std::move(engine);
     return;
@@ -353,8 +357,10 @@ void DefaultSearchManager::LoadDefaultSearchEngineFromPrefs() {
 
   std::string date_created_str;
   std::string last_modified_str;
+  std::string last_visited_str;
   url_dict->GetString(kDateCreated, &date_created_str);
   url_dict->GetString(kLastModified, &last_modified_str);
+  url_dict->GetString(kLastVisited, &last_visited_str);
 
   int64_t date_created = 0;
   if (base::StringToInt64(date_created_str, &date_created)) {
@@ -363,11 +369,17 @@ void DefaultSearchManager::LoadDefaultSearchEngineFromPrefs() {
   }
 
   int64_t last_modified = 0;
-  if (base::StringToInt64(date_created_str, &last_modified)) {
+  if (base::StringToInt64(last_modified_str, &last_modified)) {
     prefs_default_search_->last_modified =
         base::Time::FromInternalValue(last_modified);
   }
 
+  int64_t last_visited = 0;
+  if (base::StringToInt64(last_visited_str, &last_visited)) {
+    prefs_default_search_->last_visited =
+        base::Time::FromInternalValue(last_visited);
+  }
+
   url_dict->GetInteger(kUsageCount, &prefs_default_search_->usage_count);
 
   const base::ListValue* alternate_urls = NULL;