Removes the space for notification icon if it's not visible (2nd)

ash/system/status_area_widget_delegate.cc

 // Copyright (c) 2012 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/status_area_widget_delegate.h"
 
 #include "ash/ash_export.h"
 #include "ash/focus_cycler.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 65 matching lines @@
 
 void StatusAreaWidgetDelegate::UpdateLayout() {
   // Use a grid layout so that the trays can be centered in each cell, and
   // so that the widget gets laid out correctly when tray sizes change.
   views::GridLayout* layout = new views::GridLayout(this);
   SetLayoutManager(layout);
 
   views::ColumnSet* columns = layout->AddColumnSet(0);
   if (alignment_ == SHELF_ALIGNMENT_BOTTOM ||
       alignment_ == SHELF_ALIGNMENT_TOP) {
+    bool is_first_visible_child = true;
     for (int c = 0; c < child_count(); ++c) {
-      if (c != 0)
+      views::View* child = child_at(c);
+      if (!child->visible())
+        continue;
+      if (!is_first_visible_child)
         columns->AddPaddingColumn(0, kTraySpacing);
+      is_first_visible_child = false;
       columns->AddColumn(views::GridLayout::CENTER, views::GridLayout::FILL,
                          0, /* resize percent */
                          views::GridLayout::USE_PREF, 0, 0);
     }
     layout->StartRow(0, 0);
-    for (int c = child_count() - 1; c >= 0; --c)
-      layout->AddView(child_at(c));
+    for (int c = child_count() - 1; c >= 0; --c) {
+      views::View* child = child_at(c);
+      if (child->visible())
+        layout->AddView(child);
+    }
   } else {
     columns->AddColumn(views::GridLayout::FILL, views::GridLayout::CENTER,
                        0, /* resize percent */
                        views::GridLayout::USE_PREF, 0, 0);
+    bool is_first_visible_child = true;
     for (int c = child_count() - 1; c >= 0; --c) {
-      if (c != child_count() - 1)
+      views::View* child = child_at(c);
+      if (!child->visible())
+        continue;
+      if (!is_first_visible_child)
         layout->AddPaddingRow(0, kTraySpacing);
+      is_first_visible_child = false;
       layout->StartRow(0, 0);
-      layout->AddView(child_at(c));
+      layout->AddView(child);
     }
   }
   Layout();
   UpdateWidgetSize();
 }
 
 void StatusAreaWidgetDelegate::ChildPreferredSizeChanged(View* child) {
   // Need to resize the window when trays or items are added/removed.
   UpdateWidgetSize();
 }
 
+void StatusAreaWidgetDelegate::ChildVisibilityChanged(View* child) {
+  UpdateLayout();
+}
+
 void StatusAreaWidgetDelegate::UpdateWidgetSize() {
   if (GetWidget())
     GetWidget()->SetSize(GetPreferredSize());
 }
 
 }  // namespace internal
 }  // namespace ash