Block the autohide of the launcher when 'quiet mode' bubble is shown for notifications.

ash/system/web_notification/web_notification_tray.h

Index: ash/system/web_notification/web_notification_tray.h
diff --git a/ash/system/web_notification/web_notification_tray.h b/ash/system/web_notification/web_notification_tray.h
index ffc34d87ece579b6737272d600aaf8378eea6e31..0b27d229cee4007fcb915af186488db7d71caba9 100644
--- a/ash/system/web_notification/web_notification_tray.h
+++ b/ash/system/web_notification/web_notification_tray.h
@@ -64,6 +64,9 @@ class ASH_EXPORT WebNotificationTray
   // Updates tray visibility login status of the system changes.
   void UpdateAfterLoginStatusChange(user::LoginStatus login_status);
 
+  // Returns true if it should block the auto hide behavior of the launcher.
+  bool ShouldBlockLauncherAutoHide() const;
+
   // Returns true if the message center bubble is visible.
   bool IsMessageCenterBubbleVisible() const;