Revert "Reland "Ash Tray: Fix quick settings not closing after clicking on a notification.""

This reverts commit ce400cdf.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Reland "Ash Tray: Fix quick settings not closing after clicking on a notification."
>
> This is a reland of b622130a
>
> Original change's description:
> > Ash Tray: Fix quick settings not closing after clicking on a notification.
> >
> > BUG=1024100
> >
> > Change-Id: Ib30e43689842069e4647f7f455a919c62a3c7844
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928042
> > Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
> > Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#717775}
>
> Bug: 1024100
> Change-Id: Ie4e4435f0b336b77e856705512a21911704a95b8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1962799
> Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
> Commit-Queue: Ahmed Mehfooz <amehfooz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#725204}

TBR=amehfooz@chromium.org,tengs@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1024100, 1041174
Change-Id: Ica74c49ad4de3123e15196ad8ce39a09d718cb1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2001845
Commit-Queue: Tim Song <tengs@chromium.org>
Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731784}

ash/system/unified/unified_system_tray_bubble.cc

@@ -312,13 +312,17 @@ void UnifiedSystemTrayBubble::OnWindowActivated(ActivationReason reason,
     return;
   }
 
-  // Don't close the bubble if the message center is gaining activation.
+  // Don't close the bubble if the message center is gaining or losing
+  // activation.
   if (features::IsUnifiedMessageCenterRefactorEnabled() &&
       tray_->IsMessageCenterBubbleShown()) {
     views::Widget* message_center_widget =
         tray_->message_center_bubble()->GetBubbleWidget();
     if (message_center_widget ==
-        views::Widget::GetWidgetForNativeView(gained_active)) {
+            views::Widget::GetWidgetForNativeView(gained_active) ||
+        (lost_active &&
+         message_center_widget ==
+             views::Widget::GetWidgetForNativeView(lost_active))) {
       return;
     }
   }