Support painting panel in iconified mode on Windows.

chrome/browser/ui/panels/panel.h

 // Copyright (c) 2011 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 CHROME_BROWSER_UI_PANELS_PANEL_H_
 #define CHROME_BROWSER_UI_PANELS_PANEL_H_
 #pragma once
 
 #include "chrome/browser/ui/browser_window.h"
 
@@ skipping 21 matching lines @@
 class Panel : public BrowserWindow,
               public TabStripModelObserver,
               public content::NotificationObserver {
  public:
   enum ExpansionState {
    // The panel is fully expanded with both title-bar and the client-area.
    EXPANDED,
    // The panel is shown with the title-bar only.
    TITLE_ONLY,
    // The panel is shown with 3-pixel line.
-   MINIMIZED
+   MINIMIZED,
+   // The panel is put into the overflow area due to no space available in the
+   // normal display area.
+   IN_OVERFLOW
   };
 
   // The panel can be minimized to 4-pixel lines.
   static const int kMinimizedPanelHeight = 4;
 
   virtual ~Panel();
 
   // Returns the PanelManager associated with this panel.
   PanelManager* manager() const;
 
@@ skipping 222 matching lines @@
   NativePanel* native_panel_;  // Weak, owns us.
 
   ExpansionState expansion_state_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(Panel);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_PANEL_H_