Revert 151752 - Move non SystemTray specific code to TrayBackgroundView

ash/system/status_area_widget.cc

Index: ash/system/status_area_widget.cc
===================================================================
--- ash/system/status_area_widget.cc	(revision 151762)
+++ ash/system/status_area_widget.cc	(working copy)
@@ -324,12 +324,9 @@
 void StatusAreaWidget::CreateTrayViews(ShellDelegate* shell_delegate) {
   AddWebNotificationTray();
   AddSystemTray(shell_delegate);
-  // Initialize() must be called after all trays have been created.
-  if (system_tray_)
-    system_tray_->Initialize();
-  if (web_notification_tray_)
-    web_notification_tray_->Initialize();
-  UpdateAfterLoginStatusChange(system_tray_delegate_->GetUserLoginStatus());
+  // SetBorder() must be called after all trays have been created.
+  web_notification_tray_->SetBorder();
+  system_tray_->SetBorder();
 }
 
 void StatusAreaWidget::Shutdown() {
@@ -346,6 +343,7 @@
 void StatusAreaWidget::AddSystemTray(ShellDelegate* shell_delegate) {
   system_tray_ = new SystemTray(this);
   status_area_widget_delegate_->AddTray(system_tray_);
+  system_tray_->Initialize();  // Called after added to widget.
 
   if (shell_delegate) {
     system_tray_delegate_.reset(
@@ -353,6 +351,9 @@
   }
   if (!system_tray_delegate_.get())
     system_tray_delegate_.reset(new DummySystemTrayDelegate());
+
+  system_tray_->CreateItems();  // Called after delegate is created.
+  UpdateAfterLoginStatusChange(system_tray_delegate_->GetUserLoginStatus());
 }
 
 void StatusAreaWidget::AddWebNotificationTray() {