Fix status area color when immersive app is opened

Status area background color was incorrect when switching from
KioskNext home to immersive app, because shelf turns to auto-hide
mode then and both shelf and status area are not visible.

Bug: 949289
Change-Id: I28213355ea0f65d7638bd59714e50fbaceef3371
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1577944Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653016}

ash/shelf/shelf_layout_manager.cc

@@ -1299,8 +1299,6 @@ bool ShelfLayoutManager::CalculateStatusAreaVisibility(
 bool ShelfLayoutManager::ShouldRepaintStatusAreaOnStateChange(
     ShelfLayoutManager::State old_state,
     ShelfLayoutManager::State new_state) const {
-  if (!new_state.is_status_area_visible)
-    return false;
 
   if (old_state.visibility_state == new_state.visibility_state)
     return false;