Migrate old settings for ContentSettingTypes with wildcard as secondary_pattern

components/content_settings/core/browser/host_content_settings_map.h

Index: components/content_settings/core/browser/host_content_settings_map.h
diff --git a/components/content_settings/core/browser/host_content_settings_map.h b/components/content_settings/core/browser/host_content_settings_map.h
index b551d462dbb77c87a4ebbfadc53591985e59abe2..bd4240c0e9577b926f34f75a68e69c9cfae598b4 100644
--- a/components/content_settings/core/browser/host_content_settings_map.h
+++ b/components/content_settings/core/browser/host_content_settings_map.h
@@ -169,6 +169,16 @@ class HostContentSettingsMap : public content_settings::Observer,
                                      const std::string& resource_identifier,
                                      ContentSetting setting);
 
+  // Migrate old settings for those ContentSettingsType which previously
+  // would use the same pattern twice instead of using
+  // ContentSettingsPattern::Wildcard(). This has no impact on lookups using
+  // GetContentSetting (because Wildcard matches everything) but it has an
+  // impact when trying to change the existing content setting. We need to
+  // migrate the old-format keys.
+  // TODO(lshang): Remove this when clients have migrated. We should leave in
+  // some code to remove old-format settings for a long time.
+  void MigrateOldSettings();
+
   // Sets the |value| for the default scope of the url that is appropriate for
   // the given |content_type| and |resource_identifier|. Setting the value to
   // null removes the default pattern pair for this content type.