Support dragging panels to stack and snap.

chrome/browser/ui/gtk/panels/panel_gtk.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_GTK_PANELS_PANEL_GTK_H_
 #define CHROME_BROWSER_UI_GTK_PANELS_PANEL_GTK_H_
 
 #include <gtk/gtk.h>
 #include <map>
 
@@ skipping 62 matching lines @@
   // These sizes are in screen coordinates.
   virtual gfx::Size WindowSizeFromContentSize(
       const gfx::Size& content_size) const OVERRIDE;
   virtual gfx::Size ContentSizeFromWindowSize(
       const gfx::Size& window_size) const OVERRIDE;
   virtual int TitleOnlyHeight() const OVERRIDE;
   virtual bool IsPanelAlwaysOnTop() const OVERRIDE;
   virtual void SetPanelAlwaysOnTop(bool on_top) OVERRIDE;
   virtual void EnableResizeByMouse(bool enable) OVERRIDE;
   virtual void UpdatePanelMinimizeRestoreButtonVisibility() OVERRIDE;
+  virtual void UpdatePanelStackingProperty() OVERRIDE;
 
   virtual NativePanelTesting* CreateNativePanelTesting() OVERRIDE;
 
   // Overridden from ActiveWindowWatcherXObserver.
   virtual void ActiveWindowChanged(GdkWindow* active_window) OVERRIDE;
 
   bool UsingDefaultTheme() const;
 
   Panel* panel() const { return panel_.get(); }
   PaintState paint_state() const { return paint_state_; }
@@ skipping 111 matching lines @@
   // The accelerator group used to handle accelerators, owned by this object.
   GtkAccelGroup* accel_group_;
 
   // The container for the titlebar.
   scoped_ptr<PanelTitlebarGtk> titlebar_;
 
   DISALLOW_COPY_AND_ASSIGN(PanelGtk);
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_PANELS_PANEL_GTK_H_