Implement message center on Windows

ui/message_center/message_center_tray.h

Index: ui/message_center/message_center_tray.h
diff --git a/ui/message_center/message_center_tray.h b/ui/message_center/message_center_tray.h
new file mode 100644
index 0000000000000000000000000000000000000000..4d7f98a0e6b986ff4918d370ff06d55866d9096a
--- /dev/null
+++ b/ui/message_center/message_center_tray.h
@@ -0,0 +1,73 @@
+// Copyright (c) 2013 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.
+
+#ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_
+#define UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_
+
+#include "base/observer_list.h"
+#include "ui/message_center/message_center.h"
+#include "ui/message_center/message_center_export.h"
+#include "ui/message_center/message_center_tray_delegate.h"
+
+namespace message_center {
+
+class MessageBubbleBase;
+class MessagePopupBubble;
+class QuietModeBubble;
+
+// Implementation found with each supported platform's implementation of
+// MessageCenterTrayDelegate.
+MessageCenterTrayDelegate* CreateMessageCenterTray();
+
+// Class that observes a MessageCenter. Manages the popup and message center
+// bubbles. Tells the MessageCenterTrayHost when the tray is changed, as well
+// as when bubbles are shown and hidden.
+class MESSAGE_CENTER_EXPORT MessageCenterTray
+    : public message_center::MessageCenter::Observer {
+ public:
+  MessageCenterTray(MessageCenterTrayDelegate* delegate,
+                    message_center::MessageCenter* message_center);
+  virtual ~MessageCenterTray();
+
+  // Shows or updates the message center bubble and hides the popup bubble.
+  // Returns whether the message center is visible after the call, whether or
+  // not it was visible before.
+  bool ShowMessageCenterBubble();
+
+  // Returns whether the message center was visible before.
+  bool HideMessageCenterBubble();
+
+  void ToggleMessageCenterBubble();
+
+  // Causes an update if the popup bubble is already shown.
+  void ShowPopupBubble();
+
+  // Returns whether the popup was visible before.
+  bool HidePopupBubble();
+
+  bool message_center_visible() { return message_center_visible_; }
+  bool popups_visible() { return popups_visible_; }
+  MessageCenterTrayDelegate* delegate() { return delegate_; }
+  message_center::MessageCenter* message_center() { return message_center_; }
+
+  // Overridden from message_center::MessageCenter::Observer.
+  virtual void OnMessageCenterChanged(bool new_notification) OVERRIDE;
+
+ private:
+  void NotifyMessageCenterTrayChanged();
+
+  // |message_center_| is a weak pointer that must live longer than
+  // MessageCenterTray.
+  message_center::MessageCenter* message_center_;
+  bool message_center_visible_;
+  bool popups_visible_;
+  // |delegate_| is a weak pointer that must live longer than MessageCenterTray.
+  MessageCenterTrayDelegate* delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageCenterTray);
+};
+
+}  // namespace message_center
+
+#endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_H_