Revert "CrOS app list: skip visibility changes in an in valid display"

This reverts commit c113475d.

Reason for revert: Didn't really serve its purpose. Reverting.

Original change's description:
> CrOS app list: skip visibility changes in an in valid display
> 
> This is mostly useful for tests where the display ID starts off as this
> invalid ID.
> 
> Not adding a unit test in this change because after CL 1814222 at least
> two tests will fail if this regresses.
> 
> Bug: 982512
> Change-Id: Ie447aa88fda66794a722d7e9cf478749ff4f8398
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1816734
> Reviewed-by: Alex Newcomer <newcomer@chromium.org>
> Commit-Queue: Manu Cornet <manucornet@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#698656}

TBR=xiyuan@chromium.org,newcomer@chromium.org,manucornet@chromium.org

Change-Id: I4353f0ee3b10d481de13ab96be4b8c2b0801e8a5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 982512
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1819636Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699024}

ash/app_list/app_list_controller_impl.cc

@@ -1254,8 +1254,7 @@ void AppListControllerImpl::NotifyAppListVisibilityChanged(bool visible,
 
   // Skip adjacent same changes.
   if (last_visible_ == real_visibility &&
-      (display::kInvalidDisplayId == display_id ||
-       last_visible_display_id_ == display_id)) {
+      last_visible_display_id_ == display_id) {
     return;
   }