Make browser windows override_redirect when dragging tabs.

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

 // 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.
 
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 1261 matching lines @@
       ViewsDelegate::GetInstance()
           ? ViewsDelegate::GetInstance()->GetDefaultWindowIcon()
           : NULL;
   if (window_icon) {
     SetWindowIcons(gfx::ImageSkia(), *window_icon);
   }
   CreateCompositor();
   OnAcceleratedWidgetAvailable();
 }
 
+void DesktopWindowTreeHostX11::RemapAsNormalWindow() {
+  XUnmapWindow(xdisplay_, xwindow_);
+  XSetWindowAttributes swa;
+  swa.override_redirect = False;
+  XChangeWindowAttributes(xdisplay_, xwindow_, CWOverrideRedirect, &swa);
+  XMapWindow(xdisplay_, xwindow_);
+}
+
 gfx::Size DesktopWindowTreeHostX11::AdjustSize(
     const gfx::Size& requested_size_in_pixels) {
   std::vector<gfx::Display> displays =
       gfx::Screen::GetScreenByType(gfx::SCREEN_TYPE_NATIVE)->GetAllDisplays();
   // Compare against all monitor sizes. The window manager can move the window
   // to whichever monitor it wants.
   for (size_t i = 0; i < displays.size(); ++i) {
     if (requested_size_in_pixels == displays[i].GetSizeInPixel()) {
       return gfx::Size(requested_size_in_pixels.width() - 1,
                        requested_size_in_pixels.height() - 1);
@@ skipping 764 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views