Support dragging panels to stack and snap.

chrome/browser/ui/panels/native_panel_stack.h

Index: chrome/browser/ui/panels/native_panel_stack.h
diff --git a/chrome/browser/ui/panels/native_panel_stack.h b/chrome/browser/ui/panels/native_panel_stack.h
new file mode 100644
index 0000000000000000000000000000000000000000..03bf5b23b7419dfd71045beec709a48f77f3db87
--- /dev/null
+++ b/chrome/browser/ui/panels/native_panel_stack.h
@@ -0,0 +1,29 @@
+// 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_STACK_H_
+#define CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_STACK_H_
+
+#include "ui/gfx/native_widget_types.h"
+
+class StackedPanelCollection;
+namespace gfx {
+class Rect;
+}
+
+class NativePanelStack {

[Dmitry Titov, 2013/01/09 02:29:50]

This needs a class comment. What this class is for, how used, ownership etc.

[jianli, 2013/01/09 21:00:59]

Done.

+  friend class StackedPanelCollection;
+
+ public:
+  static NativePanelStack* Create(StackedPanelCollection* stack);
+  virtual ~NativePanelStack() {}
+
+ protected:
+  virtual void Close() = 0;
+  virtual void OnPanelAddedOrRemoved() = 0;
+  virtual gfx::NativeWindow GetNativeWindow() const = 0;
+  virtual void SetBounds(const gfx::Rect& bounds) = 0;
+};
+
+#endif  // CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_STACK_H_