Twenty Sixteen: Add pre-connect resource hint for Google Fonts.

When using Google Fonts, pre-connect to https://fonts.gstatic.com to improve the performance downloading the webfont files.

Props westonruter.
Fixes #44668.

Built from https://develop.svn.wordpress.org/trunk@43606


git-svn-id: http://core.svn.wordpress.org/trunk@43435 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentysixteen/functions.php

@@ -155,6 +155,27 @@ function twentysixteen_content_width() {
 }
 add_action( 'after_setup_theme', 'twentysixteen_content_width', 0 );
 
+/**
+ * Add preconnect for Google Fonts.
+ *
+ * @since Twenty Sixteen 1.6
+ *
+ * @param array  $urls           URLs to print for resource hints.
+ * @param string $relation_type  The relation type the URLs are printed.
+ * @return array $urls           URLs to print for resource hints.
+ */
+function twentysixteen_resource_hints( $urls, $relation_type ) {
+	if ( wp_style_is( 'twentysixteen-fonts', 'queue' ) && 'preconnect' === $relation_type ) {
+		$urls[] = array(
+			'href' => 'https://fonts.gstatic.com',
+			'crossorigin',
+		);
+	}
+
+	return $urls;
+}
+add_filter( 'wp_resource_hints', 'twentysixteen_resource_hints', 10, 2 );
+
 /**
  * Registers a widget area.
  *

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43605';
+$wp_version = '5.0-alpha-43606';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.