comment_num_new in core/modules/comment/comment.module

Gets the number of new comments for the current user and the specified node.

hook_cron in core/modules/system/system.api.php

Perform periodic actions.

node_cron in core/modules/node/node.module

Implements hook_cron().

node_mark in core/modules/node/node.module

Decides on the type of marker to be displayed for a given node.

views_handler_field_history_user_timestamp::render in core/modules/node/views/views_handler_field_history_user_timestamp.inc

Render the field.

views_handler_field_node_new_comments::pre_render in core/modules/comment/views/views_handler_field_node_new_comments.inc

Run before any fields are rendered.

views_handler_filter_history_user_timestamp::query in core/modules/node/views/views_handler_filter_history_user_timestamp.inc

Add this filter to the query.