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

ash/system/tray/tri_view.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/tray/tri_view.h"
 
 #include "ash/system/tray/size_range_layout.h"
 #include "base/logging.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/views/border.h"
@@ skipping 106 matching lines @@
 void TriView::SetInsets(const gfx::Insets& insets) {
   box_layout_->set_inside_border_insets(insets);
 }
 
 void TriView::SetContainerBorder(Container container,
                                  std::unique_ptr<views::Border> border) {
   GetContainer(container)->SetBorder(std::move(border));
 }
 
 void TriView::SetContainerVisible(Container container, bool visible) {
+  if (GetContainer(container)->visible() == visible)
+    return;
   GetContainer(container)->SetVisible(visible);
+  Layout();
 }
 
 void TriView::SetFlexForContainer(Container container, int flex) {
   box_layout_->SetFlexForView(GetContainer(container), flex);
 }
 
 void TriView::SetContainerLayout(
     Container container,
     std::unique_ptr<views::LayoutManager> layout_manager) {
   GetLayoutManager(container)->SetLayoutManager(std::move(layout_manager));
@@ skipping 32 matching lines @@
       return center_container_layout_manager_;
     case Container::END:
       return end_container_layout_manager_;
   }
   // Required for some compilers.
   NOTREACHED();
   return nullptr;
 }
 
 }  // namespace ash