Adding mojo calls for several lock screen related operations.

ash/public/interfaces/lock_screen.mojom

 // Copyright 2017 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.
 
 module ash.mojom;
 
 import "components/signin/public/interfaces/account_id.mojom";
 import "mojo/common/string16.mojom";
 import "mojo/common/values.mojom";
 
@@ skipping 56 matching lines @@
               AuthType auth_type,
               mojo.common.mojom.String16 initial_value);
 
   // Requests to load users in the lock screen.
   // TODO: create a mojo struct for |users|, this contains user information
   // for login/lock screen, some of which might not be needed for the new
   // view-based UI. See crbug.com/729687.
   // |users|:      A list of users who can unlock the device.
   // |show_guest|: Whether to show guest session button.
   LoadUsers(mojo.common.mojom.ListValue users, bool show_guest);
+  
+  // Requests to enable pin unlock for user in the user pod.

[jdufault, 2017/06/08 21:12:06]

nit: // Notification if pin is enabled or disabled for the given user.

[xiaoyinh(OOO Sep 11-29), 2017/06/09 00:47:10]

Thanks! Done.

+  // |account_id|:   The account id of the user in the user pod.
+  // |is_enabled|:   True if pin unlock is enabled.
+  SetPinEnabledForUser(signin.mojom.AccountId account_id, bool is_enabled);
 };
 
 // Allows ash lock screen to control a client (e.g. Chrome browser). Requests
 // often involve preferences or talk to cryptohome that is not available to ash.
 interface LockScreenClient {
   // Request user authentication in chrome.
   // If auth succeeds:
   // chrome will hide the lock screen and clear any displayed error messages.
   // If auth fails:
   // chrome will request lock screen to show error messages.
   // |account_id|:           The account id of the user we are authenticating.
   // |hashed_password|:      The hashed password of the user.
   // |authenticated_by_pin|: True if we are using pin to authenticate.
   AuthenticateUser(signin.mojom.AccountId account_id,
                    string hashed_password,
                    bool authenticated_by_pin);
 
   // Request to attempt easy unlock in chrome.
   // |account_id|:   The account id of the user we are authenticating.
   AttemptUnlock(signin.mojom.AccountId account_id);
 
   // Request to hard lock the user pod.
   // |account_id|:    The account id of the user in the user pod.
   HardlockPod(signin.mojom.AccountId account_id);
 
   // Record clicks on the lock icon in the user pod.
   // |account_id|:    The account id of the user in the user pod.
   RecordClickOnLockIcon(signin.mojom.AccountId account_id);
+  
+  // Focus user pod of user with |account_id|.
+  FocusPod(signin.mojom.AccountId account_id);
+  
+  // Notify that no user pod is focused.
+  NoPodFocused();
+  
+  // Load wallpaper of user with |account_id|.
+  LoadWallpaper(signin.mojom.AccountId account_id);
+  
+  // Sign out current user.
+  SignOutUser();
+  
+  // User with |account_id| has reached maximum incorrect password attempts.
+  MaxIncorrectPasswordAttempts(signin.mojom.AccountId account_id);
 };