Implement message center on Windows

ui/message_center/message_center_tray_host.h

Index: ui/message_center/message_center_tray_host.h
diff --git a/ui/message_center/message_center_tray_host.h b/ui/message_center/message_center_tray_host.h
new file mode 100644
index 0000000000000000000000000000000000000000..96730b76362f72000d3df35650ef531d8061f164
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+++ b/ui/message_center/message_center_tray_host.h
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+// 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.
+
+#ifndef UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_HOST_H_
+#define UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_HOST_H_
+
+#include <string>
+
+#include "ui/gfx/rect.h"
+#include "ui/message_center/message_center.h"
+#include "ui/message_center/message_center_export.h"
+#include "ui/views/bubble/tray_bubble_view.h"
+#include "ui/views/view.h"
+
+namespace ui {
+
+// System-specific code that manages the UI in the notification area for each
+// system should implement MessageCenterTrayHost.
+class MESSAGE_CENTER_EXPORT MessageCenterTrayHost {
+ public:
+  static MessageCenterTrayHost* GetInstance();
+  virtual ~MessageCenterTrayHost() {}
+
+  virtual message_center::MessageCenter* message_center() = 0;
+  // Events.
+  virtual void OnMessageCenterTrayChanged() = 0;
+  virtual void OnShowMessageCenterBubble() = 0;
+  virtual void OnHideMessageCenterBubble() = 0;
+  // System-specific information related to rendering the bubbles.
+  virtual gfx::NativeView GetBubbleWindowContainer() = 0;
+  virtual views::View* GetAnchorView() = 0;
+  virtual gfx::Rect GetAnchorRect(
+      views::Widget* anchor_widget,
+      views::TrayBubbleView::AnchorType anchor_type,
+      views::TrayBubbleView::AnchorAlignment anchor_alignment) = 0;
+  virtual views::TrayBubbleView::AnchorAlignment GetAnchorAlignment() = 0;
+  virtual void UpdateInitParams(
+      views::TrayBubbleView::InitParams* init_params) = 0;
+  virtual string16 GetAccessibleNameForBubble() = 0;
+  virtual bool CanShowPopups() = 0;
+};
+
+}  // namespace ui
+#endif  // UI_MESSAGE_CENTER_MESSAGE_CENTER_TRAY_HOST_H_