Make browser windows override_redirect when dragging tabs.

ash/host/ash_window_tree_host_unified.h

 // Copyright 2015 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 ASH_HOST_ASH_WINDOW_TREE_HOST_UNIFIED_H_
 #define ASH_HOST_ASH_WINDOW_TREE_HOST_UNIFIED_H_
 
 #include <vector>
 
 #include "ash/host/ash_window_tree_host.h"
@@ skipping 42 matching lines @@
   gfx::Transform GetRootTransform() const override;
   void SetRootTransform(const gfx::Transform& transform) override;
   gfx::Transform GetInverseRootTransform() const override;
   void UpdateRootWindowSize(const gfx::Size& host_size) override;
   void SetCapture() override;
   void ReleaseCapture() override;
   gfx::Point GetLocationOnNativeScreen() const override;
   void SetCursorNative(gfx::NativeCursor cursor) override;
   void MoveCursorToNative(const gfx::Point& location) override;
   void OnCursorVisibilityChangedNative(bool show) override;
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  void RemapAsNormalWindow() override;
+#endif
 
   // aura::WindowObserver:
   void OnWindowDestroying(aura::Window* window) override;
 
   // ui::internal::InputMethodDelegate:
   ui::EventDispatchDetails DispatchKeyEventPostIME(
       ui::KeyEvent* event) override;
 
   std::vector<AshWindowTreeHost*> mirroring_hosts_;
 
   gfx::Rect bounds_;
 
   TransformerHelper transformer_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(AshWindowTreeHostUnified);
 };
 
 }  // namespace ash
 
 #endif  // ASH_HOST_ASH_WINDOW_TREE_HOST_UNIFIED_H_