mojo api for view based lockscreen

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 877fd6c35787007f32362f599ff58ef331720504..6af7381fbeb1f40cecbeb7b66b9803c41e51ff58 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -119,6 +119,7 @@ class LinkHandlerModelFactory;
 class LocaleNotificationController;
 class LockStateController;
 class LogoutConfirmationController;
+class LockScreenController;
 class MagnificationController;
 class MaximizeModeController;
 class MediaController;
@@ -327,6 +328,9 @@ class ASH_EXPORT Shell : public SessionObserver,
   LogoutConfirmationController* logout_confirmation_controller() {
     return logout_confirmation_controller_.get();
   }
+  LockScreenController* lock_screen_controller() {
+    return lock_screen_controller_.get();
+  }
   MaximizeModeController* maximize_mode_controller() {
     return maximize_mode_controller_.get();
   }
@@ -692,6 +696,7 @@ class ASH_EXPORT Shell : public SessionObserver,
       keyboard_brightness_control_delegate_;
   std::unique_ptr<KeyboardUI> keyboard_ui_;
   std::unique_ptr<LocaleNotificationController> locale_notification_controller_;
+  std::unique_ptr<LockScreenController> lock_screen_controller_;
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
   std::unique_ptr<MaximizeModeController> maximize_mode_controller_;
   std::unique_ptr<MediaController> media_controller_;