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

chrome/browser/ui/panels/overflow_panel_strip.h

Index: chrome/browser/ui/panels/overflow_panel_strip.h
diff --git a/chrome/browser/ui/panels/overflow_panel_strip.h b/chrome/browser/ui/panels/overflow_panel_strip.h
index 3ffcf5acf5c90912a86b36cb488f5baa17981f35..4c598cddc27d1e6d167115c8c12a6a9cd10067fd 100644
--- a/chrome/browser/ui/panels/overflow_panel_strip.h
+++ b/chrome/browser/ui/panels/overflow_panel_strip.h
@@ -33,7 +33,7 @@ class OverflowPanelStrip : public PanelStrip,
   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,