[ash] Made TriView's re-layout automatically when a child container's visibility changes.

ash/system/audio/volume_view.cc

Index: ash/system/audio/volume_view.cc
diff --git a/ash/system/audio/volume_view.cc b/ash/system/audio/volume_view.cc
index 9d426359dfa6056383a15a66c70c48dcccac892e..1a7fad83d2e9c12c7787f2d79eab42a5e435eafc 100644
--- a/ash/system/audio/volume_view.cc
+++ b/ash/system/audio/volume_view.cc
@@ -174,9 +174,6 @@ void VolumeView::UpdateDeviceTypeAndMore() {
   if (is_default_view_ && !audio_handler->has_alternative_output() &&
       !audio_handler->has_alternative_input()) {
     tri_view_->SetContainerVisible(TriView::Container::END, false);
-    // TODO(tdanderson): TriView itself should trigger a relayout when the
-    // visibility of one of its containers is changed.
-    tri_view_->InvalidateLayout();
     return;
   }