Make initial focus consistent in all instances of cr-drawer.

ui/webui/resources/cr_elements/cr_drawer/cr_drawer.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/shared_vars_css.html">
 
 <dom-module id="cr-drawer">
   <template>
     <style>
       :host {
         --drawer-width: 256px;
         --transition-timing: 200ms ease;
         background-color: #fff;
@@ skipping 36 matching lines @@
         position: absolute;
         right: 0;
         top: 0;
         transition: opacity var(--transition-timing);
       }
 
       :host(.opening)::backdrop {
         opacity: 1;
       }
 
-      :host ::content .drawer-header {
+      .drawer-header {
         -webkit-padding-start: 24px;
         align-items: center;
         border-bottom: var(--cr-separator-line);
         display: flex;
         font-size: 123.08%; /* go to 16px from 13px */
         min-height: 56px;
+        outline: none;
       }
 
       :host ::content .drawer-content {
         height: calc(100% - 56px);
         overflow: auto;
       }
     </style>
     <div id="container" on-tap="onContainerTap_">
+      <div class="drawer-header" tabindex="-1">[[title]]</div>
       <content></content>
     </div>
   </template>
 </dom-module>
 <script src="cr_drawer.js"></script>