Issue #1529814 by mgifford, JohnAlbin, ibullock, dcmouyard, mark.labrecque, andrewmacpherson, vegantriathlete: Fixed skiplink behavior for Webkit browsers.

core/modules/system/templates/page.html.twig

@@ -109,7 +109,7 @@
   {{ page.help }}
 
   <main role="main">
-    <a id="main-content"></a>{# link is in html.html.twig #}
+    <a id="main-content" tabindex="-1"></a>{# link is in html.html.twig #}
 
     <div class="layout-content">
       {{ page.highlighted }}

core/themes/bartik/templates/page.html.twig

@@ -147,7 +147,7 @@
 
     <main id="content" class="column" role="main"><section class="section">
       {% if page.highlighted %}<div id="highlighted">{{ page.highlighted }}</div>{% endif %}
-      <a id="main-content"></a>
+      <a id="main-content" tabindex="-1"></a>
       {{ title_prefix }}
         {% if title %}
           <h1 class="title" id="page-title">

core/themes/seven/templates/page.html.twig

@@ -84,7 +84,7 @@
     {{ breadcrumb }}
 
     <main id="content" class="clearfix" role="main">
-      <div class="visually-hidden"><a id="main-content"></a></div>
+      <div class="visually-hidden"><a id="main-content" tabindex="-1"></a></div>
       {% if messages %}
         <div id="console" class="clearfix">{{ messages }}</div>
       {% endif %}