md settings: Small changes to lock screen.

chrome/browser/resources/settings/people_page/password_prompt_dialog.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  *
  * 'settings-password-prompt-dialog' shows a dialog which asks for the user to
  * enter their password. It validates the password is correct. Once the user has
  * entered their account password, the page fires an 'authenticated' event and
@@ skipping 92 matching lines @@
     if (!dialog.isConnected) {
       setTimeout(this.open.bind(this));
       return;
     }
 
     if (this.$.dialog.open)
       return;
 
     this.writeUma_(LockScreenProgress.START_SCREEN_LOCK);
     this.$.dialog.showModal();
+    this.async(function() {
+      this.$.passwordInput.shadowRoot.querySelector('#input').focus();
+    }.bind(this));
   },
 
   /** @private */
   onCancelTap_: function() {
     if (this.$.dialog.open)
       this.$.dialog.close();
   },
 
   /**
    * Called whenever the dialog is closed.
@@ skipping 75 matching lines @@
     this.quickUnlockPrivate_.getActiveModes(function(modes) {
       var credentials =
           /** @type {!Array<string>} */ (Array(modes.length).fill(''));
       this.quickUnlockPrivate_.setModes(
           this.password_, modes, credentials, onCheck);
     }.bind(this));
   }
 });
 
 })();