Write last_modified date to Content Settings in the PrefProvider

components/content_settings/core/browser/content_settings_pref.h

Index: components/content_settings/core/browser/content_settings_pref.h
diff --git a/components/content_settings/core/browser/content_settings_pref.h b/components/content_settings/core/browser/content_settings_pref.h
index 77c6d031fb1c6256122669d3547924a5959a654a..5d75a8d225afd93105648270e0f49e9bde66f0fe 100644
--- a/components/content_settings/core/browser/content_settings_pref.h
+++ b/components/content_settings/core/browser/content_settings_pref.h
@@ -43,6 +43,7 @@ class ContentSettingsPref {
                       PrefChangeRegistrar* registrar,
                       const std::string& pref_name,
                       bool incognito,
+                      bool store_last_modified,
                       NotifyObserversCallback notify_callback);
   ~ContentSettingsPref();
 
@@ -56,6 +57,13 @@ class ContentSettingsPref {
                          const ResourceIdentifier& resource_identifier,
                          base::Value* value);
 
+  // Delete a setting if its |last_modified| date is greater or equal to
+  // |begin_time|.
+  void DeleteWebsiteSettingAfterDate(
+      const ContentSettingsPattern& primary_pattern,
+      const ContentSettingsPattern& secondary_pattern,
+      base::Time begin_time);
+
   void ClearPref();
 
   void ClearAllContentSettingsRules();
@@ -77,11 +85,11 @@ class ContentSettingsPref {
   // value to the obsolete preference. When calling this function, |lock_|
   // should not be held, since this function will send out notifications of
   // preference changes.
-  void UpdatePref(
-      const ContentSettingsPattern& primary_pattern,
-      const ContentSettingsPattern& secondary_pattern,
-      const ResourceIdentifier& resource_identifier,
-      const base::Value* value);
+  void UpdatePref(const ContentSettingsPattern& primary_pattern,
+                  const ContentSettingsPattern& secondary_pattern,
+                  const ResourceIdentifier& resource_identifier,
+                  const base::Time last_modified,
+                  const base::Value* value);
 
   static void CanonicalizeContentSettingsExceptions(
       base::DictionaryValue* all_settings_dictionary);
@@ -105,6 +113,8 @@ class ContentSettingsPref {
 
   bool is_incognito_;
 
+  bool store_last_modified_;
+
   // Whether we are currently updating preferences, this is used to ignore
   // notifications from the preferences service that we triggered ourself.
   bool updating_preferences_;