Start delegating notifications to MessageCenter on Windows.

ash/system/web_notification/web_notification_tray.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/web_notification/web_notification_tray.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/tray_bubble_wrapper.h"
@@ skipping 65 matching lines @@
   scoped_ptr<internal::TrayBubbleWrapper> bubble_wrapper_;
 };
 
 }  // namespace internal
 
 WebNotificationTray::WebNotificationTray(
     internal::StatusAreaWidget* status_area_widget)
     : internal::TrayBackgroundView(status_area_widget),
       button_(NULL),
       show_message_center_on_unlock_(false) {
-  message_center_ = message_center::MessageCenter::GetInstance();
+  message_center_.reset(new message_center::MessageCenter);

[stevenjb, 2013/01/17 01:53:44]

This is a problem. We may have more than one WebNotificationTray instance in
Ash.

Instead, instantiate a MessageCenter instance in ash::Shell and set this to
ash::Shell::GetInstance()->message_center();

   message_center_->AddObserver(this);
   button_ = new views::ImageButton(this);
   button_->set_triggerable_event_flags(
       ui::EF_LEFT_MOUSE_BUTTON | ui::EF_RIGHT_MOUSE_BUTTON);
   tray_container()->AddChildView(button_);
   SetVisible(false);
   UpdateTray();
 }
 
 WebNotificationTray::~WebNotificationTray() {
-  // Ensure the message center doesn't notify a destroyed object.
+  // Ensure the message center doesn't notify an object under destruction.
   message_center_->RemoveObserver(this);
   // Release any child views that might have back pointers before ~View().
   message_center_bubble_.reset();
   popup_bubble_.reset();
   if (quiet_mode_bubble() && quiet_mode_bubble_->GetBubbleWidget())
     quiet_mode_bubble_->GetBubbleWidget()->RemoveObserver(this);
   quiet_mode_bubble_.reset();
 }
 
 void WebNotificationTray::ShowMessageCenterBubble() {
   if (status_area_widget()->login_status() == user::LOGGED_IN_LOCKED)
     return;
   if (quiet_mode_bubble())
     quiet_mode_bubble_.reset();
   if (message_center_bubble()) {
     UpdateTray();
     return;
   }
   // Indicate that the message center is visible. Clears the unread count.
   message_center_->SetMessageCenterVisible(true);
   UpdateTray();
   HidePopupBubble();
   message_center::MessageCenterBubble* bubble =
-      new message_center::MessageCenterBubble(message_center_);
+      new message_center::MessageCenterBubble(message_center_.get());
   // Sets the maximum height of the bubble based on the screen.
   // TODO(mukai): move this to WebNotificationBubbleWrapper if it's safe
   // to set the height of the popup.
   int max_height = 0;
   if (GetShelfLayoutManager()->GetAlignment() == SHELF_ALIGNMENT_BOTTOM) {
     gfx::Rect shelf_bounds = GetShelfLayoutManager()->GetIdealBounds();
     max_height = shelf_bounds.y();
   } else {
     // Assume that the bottom line of the status area widget and the bubble are
     // aligned.
@@ skipping 33 matching lines @@
     return;
   if (!status_area_widget()->ShouldShowWebNotifications())
     return;
   UpdateTray();
   if (popup_bubble()) {
     popup_bubble()->bubble()->ScheduleUpdate();
   } else if (message_center_->HasPopupNotifications()) {
     popup_bubble_.reset(
         new internal::WebNotificationBubbleWrapper(
             this, new message_center::MessagePopupBubble(
-                message_center_)));
+                message_center_.get())));
   }
 }
 
 void WebNotificationTray::HidePopupBubble() {
   popup_bubble_.reset();
 }
 
 bool WebNotificationTray::ShouldShowQuietModeBubble(const ui::Event& event) {
   // TODO(mukai): Add keyboard event handler.
   if (!event.IsMouseEvent())
@@ skipping 219 matching lines @@
 
 message_center::MessagePopupBubble*
 WebNotificationTray::GetPopupBubbleForTest() {
   if (!popup_bubble_.get())
     return NULL;
   return static_cast<message_center::MessagePopupBubble*>(
       popup_bubble_->bubble());
 }
 
 }  // namespace ash