Make browser windows override_redirect when dragging tabs.

ash/host/ash_window_tree_host_x11.cc

 // Copyright 2014 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.
 
 #include "ash/host/ash_window_tree_host_x11.h"
 
 #include <X11/extensions/Xfixes.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
@@ skipping 108 matching lines @@
     ConfineCursorToRootWindow();
   }
 }
 
 gfx::Insets AshWindowTreeHostX11::GetHostInsets() const {
   return transformer_helper_.GetHostInsets();
 }
 
 aura::WindowTreeHost* AshWindowTreeHostX11::AsWindowTreeHost() { return this; }
 
+void AshWindowTreeHostX11::RemapAsNormalWindow() {
+  NOTREACHED();
+}
+
 void AshWindowTreeHostX11::PrepareForShutdown() {
   // Block the root window from dispatching events because it is weird for a
   // ScreenPositionClient not to be attached to the root window and for
   // ui::EventHandlers to be unable to convert the event's location to screen
   // coordinates.
   window()->SetEventTargeter(
       scoped_ptr<ui::EventTargeter>(new ui::NullEventTargeter));
 
   if (ui::PlatformEventSource::GetInstance()) {
     // Block X events which are not turned into ui::Events from getting
@@ skipping 153 matching lines @@
 #endif
 
 AshWindowTreeHost* AshWindowTreeHost::Create(
     const AshWindowTreeHostInitParams& init_params) {
   if (init_params.offscreen)
     return new AshWindowTreeHostUnified(init_params.initial_bounds);
   return new AshWindowTreeHostX11(init_params.initial_bounds);
 }
 
 }  // namespace ash