Make browser windows override_redirect when dragging tabs.

ui/aura/window_tree_host.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 UI_AURA_WINDOW_TREE_HOST_H_
 #define UI_AURA_WINDOW_TREE_HOST_H_
 
 #include <vector>
 
 #include "base/event_types.h"
@@ skipping 152 matching lines @@
   // Gets/Sets the size of the WindowTreeHost (in pixels).
   virtual gfx::Rect GetBounds() const = 0;
   virtual void SetBounds(const gfx::Rect& bounds_in_pixels) = 0;
 
   // Sets the OS capture to the root window.
   virtual void SetCapture() = 0;
 
   // Releases OS capture of the root window.
   virtual void ReleaseCapture() = 0;
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  virtual void RemapAsNormalWindow() = 0;

[Daniel Erat, 2016/01/19 20:36:22]

nit: add a comment like, "Remaps as a normal (i.e. non-override-redirect)
window."

[stapelberg, 2016/01/20 13:31:09]

Done.

+#endif
+
  protected:
   friend class TestScreen;  // TODO(beng): see if we can remove/consolidate.
 
   WindowTreeHost();
   void DestroyCompositor();
   void DestroyDispatcher();
 
   void CreateCompositor();
   void OnAcceleratedWidgetAvailable();
 
@@ skipping 57 matching lines @@
 
   // Whether the InputMethod instance is owned by this WindowTreeHost.
   bool owned_input_method_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHost);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_TREE_HOST_H_