Add ash UI for third-party VPNs

ash/system/tray/hover_highlight_view.cc

Index: ash/system/tray/hover_highlight_view.cc
diff --git a/ash/system/tray/hover_highlight_view.cc b/ash/system/tray/hover_highlight_view.cc
index cc2c5840c3028b876f21b0c376d37644ba733f38..884de5659b55662f8644ade78830d9c3580ef9da 100644
--- a/ash/system/tray/hover_highlight_view.cc
+++ b/ash/system/tray/hover_highlight_view.cc
@@ -197,6 +197,10 @@ void HoverHighlightView::OnGestureEvent(ui::GestureEvent* event) {
   ActionableView::OnGestureEvent(event);
 }
 
+void HoverHighlightView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
+  SetHoverHighlight(IsMouseHovered());
+}
+
 void HoverHighlightView::OnEnabledChanged() {
   for (int i = 0; i < child_count(); ++i)
     child_at(i)->SetEnabled(enabled());