Don't close ash notifications on deactivate

ash/system/tray/system_tray_bubble.cc

Index: ash/system/tray/system_tray_bubble.cc
diff --git a/ash/system/tray/system_tray_bubble.cc b/ash/system/tray/system_tray_bubble.cc
index 2f83ab49de539a71120369ef81c322c9ab7b1235..7145615c1cc0a4fe8ef09f0696fd2e7dc954d2cf 100644
--- a/ash/system/tray/system_tray_bubble.cc
+++ b/ash/system/tray/system_tray_bubble.cc
@@ -380,6 +380,8 @@ void SystemTrayBubble::InitView(const InitParams& init_params) {
   anchor_type_ = init_params.anchor_type;
   bubble_view_ = new SystemTrayBubbleView(
       init_params.anchor, this, init_params.can_activate);
+  if (bubble_type_ == BUBBLE_TYPE_NOTIFICATION)
+    bubble_view_->set_close_on_deactivate(false);
 
   CreateItemViews(init_params.login_status);