Prepare SystemTray to support notifications

ash/system/date/tray_date.cc

Index: ash/system/date/tray_date.cc
diff --git a/ash/system/date/tray_date.cc b/ash/system/date/tray_date.cc
index fb8d82954cf26eb239c0ef60f0fec25f251a0ebe..846064fdcaf703f03fe79314237600944902ba1b 100644
--- a/ash/system/date/tray_date.cc
+++ b/ash/system/date/tray_date.cc
@@ -35,14 +35,16 @@
 namespace ash {
 namespace internal {
 
-TrayDate::TrayDate() {
+TrayDate::TrayDate()
+    : date_tray_(NULL) {
 }
 
 TrayDate::~TrayDate() {
 }
 
 views::View* TrayDate::CreateTrayView(user::LoginStatus status) {
-  date_tray_.reset(new tray::DateView(tray::DateView::TIME));
+  DCHECK(date_tray_ == NULL);
+  date_tray_ = new tray::DateView(tray::DateView::TIME);
   date_tray_->set_border(
       views::Border::CreateEmptyBorder(0, 10, 0, 7));
   SetupLabelForTray(date_tray_->label());
@@ -51,7 +53,7 @@ views::View* TrayDate::CreateTrayView(user::LoginStatus status) {
       font.DeriveFont(0, font.GetStyle() & ~gfx::Font::BOLD));
 
   views::View* view = new TrayItemView;
-  view->AddChildView(date_tray_.get());
+  view->AddChildView(date_tray_);
   return view;
 }
 
@@ -64,7 +66,7 @@ views::View* TrayDate::CreateDetailedView(user::LoginStatus status) {
 }
 
 void TrayDate::DestroyTrayView() {
-  date_tray_.reset();
+  date_tray_ = NULL;
 }
 
 void TrayDate::DestroyDefaultView() {