Login and Registration: Add descriptive h1 on login screens.

Add an `h1` heading with the existing `login_header()` text string on each view of the login screen. Mark the existing `h1`, used to wrap the WordPress logo, with `role="presentation"`, to remove it from the headings hierarchy.

Props roytanck, joedolson, ryokuhi, sabernhardt, pamprn, nagpai, mukesh27.
Fixes #51786.

git-svn-id: https://develop.svn.wordpress.org/trunk@59138 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/login.css

@@ -224,7 +224,7 @@ p {
 	margin: 1.1em 0;
 }
 
-.login h1.admin-email__heading {
+.login .admin-email__heading {
 	border-bottom: 1px #f0f0f1 solid;
 	color: #50575e;
 	font-weight: normal;
@@ -269,11 +269,11 @@ p {
 	vertical-align: baseline;
 }
 
-.login h1 {
+.login .wp-login-logo {
 	text-align: center;
 }
 
-.login h1 a {
+.login .wp-login-logo a {
 	background-image: url(../images/w-logo-blue.png?ver=20131202);
 	background-image: none, url(../images/wordpress-logo.svg?ver=20131107);
 	background-size: 84px;
@@ -323,13 +323,13 @@ p {
 
 .login #nav a:hover,
 .login #backtoblog a:hover,
-.login h1 a:hover {
+.login .wp-login-logo a:hover {
 	color: #135e96;
 }
 
 .login #nav a:focus,
 .login #backtoblog a:focus,
-.login h1 a:focus {
+.login .wp-login-logo a:focus {
 	color: #043959;
 }
 
@@ -390,7 +390,7 @@ body.interim-login {
 	margin: 5px auto 20px;
 }
 
-.interim-login.login h1 a {
+.interim-login.login .wp-login-logo a {
 	width: auto;
 }
 

src/wp-login.php

@@ -210,10 +210,16 @@ function login_header( $title = null, $message = '', $wp_error = null ) {
 	 * @since 4.6.0
 	 */
 	do_action( 'login_header' );
-
+	?>
+	<?php
+	if ( 'confirm_admin_email' !== $action && ! empty( $title ) ) :
+		?>
+		<h1 class="screen-reader-text"><?php echo $title; ?></h1>
+		<?php
+	endif;
 	?>
 	<div id="login">
-		<h1><a href="<?php echo esc_url( $login_header_url ); ?>"><?php echo $login_header_text; ?></a></h1>
+		<h1 role="presentation" class="wp-login-logo"><a href="<?php echo esc_url( $login_header_url ); ?>"><?php echo $login_header_text; ?></a></h1>
 	<?php
 	/**
 	 * Filters the message to display above the login form.
@@ -420,6 +426,7 @@ function login_footer( $input_id = '' ) {
 				</div>
 		<?php } ?>
 	<?php } ?>
+
 	<?php
 
 	if ( ! empty( $input_id ) ) {