Support detaching/attaching panels via inter-strip drags.

chrome/browser/ui/panels/native_panel.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_NATIVE_PANEL_H_
 #define CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_H_
 #pragma once
 
 #include "chrome/browser/ui/panels/panel.h"
 #include "ui/gfx/native_widget_types.h"
@@ skipping 70 matching lines @@
   // the panel put in the overflow area.
   virtual gfx::Size IconOnlySize() const = 0;
 
   // Brings the panel to the top of the z-order without activating it. This
   // will make sure that the panel is not obscured by other top-most windows.
   virtual void EnsurePanelFullyVisible() = 0;
 
   // Sets whether the panel app icon is visible (usually refers to the app icons
   // in the desktop bar).
   virtual void SetPanelAppIconVisibility(bool visible) = 0;
+
+  // Sets whether the panel window is always on top.
+  virtual void SetPanelAlwaysOnTop(bool on_top) = 0;
 };
 
 // A NativePanel utility interface used for accessing elements of the
 // native panel used only by test automation.
 class NativePanelTesting {
  public:
   static NativePanelTesting* Create(NativePanel* native_panel);
   virtual ~NativePanelTesting() {}
 
   // |mouse_location| is in screen coordinates.
@@ skipping 10 matching lines @@
   // Verifies, on a deepest possible level, if the native panel is really
   // active, i.e. the titlebar is painted per its active state.
   virtual bool VerifyActiveState(bool is_active) = 0;
   virtual void WaitForWindowCreationToComplete() const { }
 
   virtual bool IsWindowSizeKnown() const = 0;
   virtual bool IsAnimatingBounds() const = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_H_