MD Settings: Make heading focusable in side nav.

chrome/browser/resources/settings/settings_ui/settings_ui.html

Index: chrome/browser/resources/settings/settings_ui/settings_ui.html
diff --git a/chrome/browser/resources/settings/settings_ui/settings_ui.html b/chrome/browser/resources/settings/settings_ui/settings_ui.html
index fc366132325763b0ce4d4c1934cb290d74c1c29b..268aff11f2bc799ed23e787318d9ac1f0db9662d 100644
--- a/chrome/browser/resources/settings/settings_ui/settings_ui.html
+++ b/chrome/browser/resources/settings/settings_ui/settings_ui.html
@@ -37,6 +37,10 @@
         overflow: hidden;  /* Prevent double scroll bar bugs. */
       }
 
+      .drawer-header {
+        outline: none;
+      }
+
       paper-header-panel {
         flex: 1;
       }
@@ -81,7 +85,7 @@
         show-menu>
     </cr-toolbar>
     <dialog id="drawer" is="cr-drawer">
-      <div class="drawer-header">$i18n{settings}</div>
+      <div class="drawer-header" tabindex="-1">$i18n{settings}</div>

[Dan Beam, 2017/03/06 20:37:58]

the difference is that .drawer-header actually live outside of <dialog
is="cr-drawer"> and there's a <content> slot.

what i did was change the *inside* of cr-dialog

does that make sense?

       <div class="drawer-content">
         <template is="dom-if" id="drawerTemplate">
           <settings-menu page-visibility="[[pageVisibility_]]"