Index: src/wp-admin/includes/schema.php
===================================================================
--- src/wp-admin/includes/schema.php	(revision 43378)
+++ src/wp-admin/includes/schema.php	(working copy)
@@ -535,6 +535,9 @@
 
 		// 4.9.6
 		'wp_page_for_privacy_policy'      => 0,
+		
+		// 4.9.7
+		'show_comments_cookies_opt_in'    => 0,
 	);
 
 	// 3.3
Index: src/wp-admin/options-discussion.php
===================================================================
--- src/wp-admin/options-discussion.php	(revision 43378)
+++ src/wp-admin/options-discussion.php	(working copy)
@@ -85,6 +85,13 @@
 ?>
 </label>
 <br />
+
+<label for="show_comments_cookies_opt_in">
+<input name="show_comments_cookies_opt_in" type="checkbox" id="show_comments_cookies_opt_in" value="1" <?php checked( '1', get_option( 'show_comments_cookies_opt_in' ) ); ?> />
+<?php _e( 'Show comments cookies opt-in checkbox.' ); ?>
+</label>
+<br />
+
 <label for="thread_comments">
 <input name="thread_comments" type="checkbox" id="thread_comments" value="1" <?php checked( '1', get_option( 'thread_comments' ) ); ?> />
 <?php
Index: src/wp-admin/options.php
===================================================================
--- src/wp-admin/options.php	(revision 43378)
+++ src/wp-admin/options.php	(working copy)
@@ -80,12 +80,71 @@
 	);
 }
 
-$whitelist_options         = array(
-	'general'    => array( 'blogname', 'blogdescription', 'gmt_offset', 'date_format', 'time_format', 'start_of_week', 'timezone_string', 'WPLANG', 'new_admin_email' ),
-	'discussion' => array( 'default_pingback_flag', 'default_ping_status', 'default_comment_status', 'comments_notify', 'moderation_notify', 'comment_moderation', 'require_name_email', 'comment_whitelist', 'comment_max_links', 'moderation_keys', 'blacklist_keys', 'show_avatars', 'avatar_rating', 'avatar_default', 'close_comments_for_old_posts', 'close_comments_days_old', 'thread_comments', 'thread_comments_depth', 'page_comments', 'comments_per_page', 'default_comments_page', 'comment_order', 'comment_registration' ),
-	'media'      => array( 'thumbnail_size_w', 'thumbnail_size_h', 'thumbnail_crop', 'medium_size_w', 'medium_size_h', 'large_size_w', 'large_size_h', 'image_default_size', 'image_default_align', 'image_default_link_type' ),
-	'reading'    => array( 'posts_per_page', 'posts_per_rss', 'rss_use_excerpt', 'show_on_front', 'page_on_front', 'page_for_posts', 'blog_public' ),
-	'writing'    => array( 'default_category', 'default_email_category', 'default_link_category', 'default_post_format' ),
+$whitelist_options = array(
+	'general'    => array(
+						'blogname',
+						'blogdescription',
+						'gmt_offset',
+						'date_format',
+						'time_format',
+						'start_of_week',
+						'timezone_string',
+						'WPLANG',
+						'new_admin_email',
+					),
+	'discussion' => array(
+						'default_pingback_flag',
+						'default_ping_status',
+						'default_comment_status',
+						'comments_notify',
+						'moderation_notify',
+						'comment_moderation',
+						'require_name_email',
+						'comment_whitelist',
+						'comment_max_links',
+						'moderation_keys',
+						'blacklist_keys',
+						'show_avatars',
+						'avatar_rating',
+						'avatar_default',
+						'close_comments_for_old_posts',
+						'close_comments_days_old',
+						'thread_comments',
+						'thread_comments_depth',
+						'page_comments',
+						'comments_per_page',
+						'default_comments_page',
+						'comment_order',
+						'comment_registration',
+						'show_comments_cookies_opt_in',
+					),
+	'media'      => array(
+						'thumbnail_size_w',
+						'thumbnail_size_h',
+						'thumbnail_crop',
+						'medium_size_w',
+						'medium_size_h',
+						'large_size_w',
+						'large_size_h',
+						'image_default_size',
+						'image_default_align',
+						'image_default_link_type',
+					),
+	'reading'    => array(
+						'posts_per_page',
+						'posts_per_rss',
+						'rss_use_excerpt',
+						'show_on_front',
+						'page_on_front',
+						'page_for_posts',
+						'blog_public',
+					),
+	'writing'    => array(
+						'default_category',
+						'default_email_category',
+						'default_link_category',
+						'default_post_format',
+					),
 );
 $whitelist_options['misc'] = $whitelist_options['options'] = $whitelist_options['privacy'] = array();
 
Index: src/wp-includes/comment-template.php
===================================================================
--- src/wp-includes/comment-template.php	(revision 43378)
+++ src/wp-includes/comment-template.php	(working copy)
@@ -2271,7 +2271,7 @@
 					 '<input id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" maxlength="200" /></p>',
 	);
 
-	if ( has_action( 'set_comment_cookies', 'wp_set_comment_cookies' ) ) {
+	if ( has_action( 'set_comment_cookies', 'wp_set_comment_cookies' ) && get_option( 'show_comments_cookies_opt_in' ) ) {
 		$consent           = empty( $commenter['comment_author_email'] ) ? '' : ' checked="checked"';
 		$fields['cookies'] = '<p class="comment-form-cookies-consent"><input id="wp-comment-cookies-consent" name="wp-comment-cookies-consent" type="checkbox" value="yes"' . $consent . ' />' .
 							 '<label for="wp-comment-cookies-consent">' . __( 'Save my name, email, and website in this browser for the next time I comment.' ) . '</label></p>';