[Welcome Tour] Handle the actions that change the session state

This CL ensures that the accelerator actions that modify the session
states, such as the lock screen action, are handled properly.

When `WelcomeTourAcceleratorHandler` receives these accelerator
actions, the running tour is aborted. Meanwhile, these actions
continue to perform as usual.

Bug: b/287483131
Change-Id: I1b0f2307d693946d0ef7150de060a83b59941efd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4712365
Reviewed-by: David Black <dmblack@google.com>
Commit-Queue: Andrew Xu <andrewxu@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1175826}

diff --git a/ash/ash_element_identifiers.h b/ash/ash_element_identifiers.h
index 61a9da3..d5693b4 100644
--- a/ash/ash_element_identifiers.h
+++ b/ash/ash_element_identifiers.h

@@ -33,6 +33,9 @@
 // Uniquely identifies the home (launcher) button.
 DECLARE_EXPORTED_ELEMENT_IDENTIFIER_VALUE(ASH_EXPORT, kHomeButtonElementId);
 
+// Uniquely identifies the `LoginUserView`.
+DECLARE_EXPORTED_ELEMENT_IDENTIFIER_VALUE(ASH_EXPORT, kLoginUserViewElementId);
+
 DECLARE_EXPORTED_ELEMENT_IDENTIFIER_VALUE(
     ASH_EXPORT,
     kQuickSettingsSettingsButtonElementId);