Editor: Use Beacon API over sync request

See https://www.w3.org/TR/beacon/ for more information.


Built from https://develop.svn.wordpress.org/trunk@38425


git-svn-id: http://core.svn.wordpress.org/trunk@38366 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/post.js

@@ -407,16 +407,31 @@ jQuery(document).ready( function($) {
 			return;
 		}
 
-		$.ajax({
-			type: 'POST',
-			url: ajaxurl,
-			async: false,
-			data: {
-				action: 'wp-remove-post-lock',
-				_wpnonce: $('#_wpnonce').val(),
-				post_ID: $('#post_ID').val(),
-				active_post_lock: $('#active_post_lock').val()
+		var data = {
+			action: 'wp-remove-post-lock',
+			_wpnonce: $('#_wpnonce').val(),
+			post_ID: $('#post_ID').val(),
+			active_post_lock: $('#active_post_lock').val()
+		};
+
+		if (window.FormData && window.navigator.sendBeacon) {
+			var formData = new window.FormData();
+
+			$.each(data, function(key, value) {
+				formData.append(key, value);
+			});
+
+			if (window.navigator.sendBeacon(ajaxurl, formData)) {
+				return;
 			}
+		}
+
+		// Fall back to a synchronous POST request.
+		// See https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon
+		$.post({
+			async: false,
+			data: data,
+			url: ajaxurl
 		});
 	});
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38424';
+$wp_version = '4.7-alpha-38425';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.