Enforce that only one constrained window is displayed at once per tab.

chrome/browser/views/constrained_window_win.h

 // Copyright (c) 2006-2008 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_VIEWS_CONSTRAINED_WINDOW_WIN_H_
 #define CHROME_BROWSER_VIEWS_CONSTRAINED_WINDOW_WIN_H_
 
 #include "base/gfx/rect.h"
 #include "chrome/browser/tab_contents/constrained_window.h"
 #include "chrome/browser/tab_contents/tab_contents_delegate.h"
@@ skipping 17 matching lines @@
  public:
   virtual ~ConstrainedWindowWin();
 
   // Returns the TabContents that constrains this Constrained Window.
   TabContents* owner() const { return owner_; }
 
   // Overridden from views::Window:
   virtual views::NonClientFrameView* CreateFrameViewForWindow();
 
   // Overridden from ConstrainedWindow:
+  virtual void ShowConstrainedWindow();
   virtual void CloseConstrainedWindow();
   virtual std::wstring GetWindowTitle() const;
   virtual const gfx::Rect& GetCurrentBounds() const;
 
  protected:
   // Windows message handlers:
   virtual void OnDestroy();
   virtual void OnFinalMessage(HWND window);
   virtual LRESULT OnMouseActivate(HWND window, UINT hittest_code, UINT message);
   virtual void OnWindowPosChanged(WINDOWPOS* window_pos);
@@ skipping 17 matching lines @@
   // the constrained title bar.
   gfx::Point anchor_point_;
 
   // Current display rectangle (relative to owner_'s visible area).
   gfx::Rect current_bounds_;
 
   DISALLOW_COPY_AND_ASSIGN(ConstrainedWindowWin);
 };
 
 #endif  // #ifndef CHROME_BROWSER_VIEWS_CONSTRAINED_WINDOW_WIN_H_