Cleanup to keep panel from manipulating its panel strip assignment directly.

chrome/browser/ui/panels/detached_panel_strip.h

 // 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 CHROME_BROWSER_UI_PANELS_DETACHED_PANEL_STRIP_H_
 #define CHROME_BROWSER_UI_PANELS_DETACHED_PANEL_STRIP_H_
 #pragma once
 
 #include <set>
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
  public:
   typedef std::set<Panel*> Panels;
 
   explicit DetachedPanelStrip(PanelManager* panel_manager);
   virtual ~DetachedPanelStrip();
 
   // PanelStrip OVERRIDES:
   virtual void SetDisplayArea(const gfx::Rect& display_area) OVERRIDE;
   virtual void RefreshLayout() OVERRIDE;
   virtual void AddPanel(Panel* panel) OVERRIDE;
-  virtual bool RemovePanel(Panel* panel) OVERRIDE;
+  virtual void RemovePanel(Panel* panel) OVERRIDE;
   virtual void CloseAll() OVERRIDE;
   virtual void ResizePanelWindow(
       Panel* panel,
       const gfx::Size& preferred_window_size) OVERRIDE;
   virtual void OnPanelAttentionStateChanged(Panel* panel) OVERRIDE;
   virtual void ActivatePanel(Panel* panel) OVERRIDE;
   virtual void MinimizePanel(Panel* panel) OVERRIDE;
   virtual void RestorePanel(Panel* panel) OVERRIDE;
   virtual bool CanShowPanelAsActive(const Panel* panel) const OVERRIDE;
   virtual bool CanDragPanel(const Panel* panel) const OVERRIDE;
@@ skipping 12 matching lines @@
   // All panels in the panel strip must fit within this area.
   gfx::Rect display_area_;
 
   // Collection of all panels.
   Panels panels_;
 
   DISALLOW_COPY_AND_ASSIGN(DetachedPanelStrip);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_DETACHED_PANEL_STRIP_H_