linux aura: Show the drag-image when available.

ui/views/widget/desktop_aura/desktop_root_window_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_root_window_host_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 71 matching lines @@
   "_NET_WM_PING",
   "_NET_WM_STATE",
   "_NET_WM_STATE_ABOVE",
   "_NET_WM_STATE_FULLSCREEN",
   "_NET_WM_STATE_HIDDEN",
   "_NET_WM_STATE_MAXIMIZED_HORZ",
   "_NET_WM_STATE_MAXIMIZED_VERT",
   "_NET_WM_STATE_SKIP_TASKBAR",
   "_NET_WM_WINDOW_OPACITY",
   "_NET_WM_WINDOW_TYPE",
+  "_NET_WM_WINDOW_TYPE_DND",
   "_NET_WM_WINDOW_TYPE_MENU",
   "_NET_WM_WINDOW_TYPE_NORMAL",
   "_NET_WM_WINDOW_TYPE_NOTIFICATION",
   "_NET_WM_WINDOW_TYPE_TOOLTIP",
   "XdndActionAsk",
   "XdndActionCopy"
   "XdndActionLink",
   "XdndActionList",
   "XdndActionMove",
   "XdndActionPrivate",
@@ skipping 814 matching lines @@
     const Widget::InitParams& params) {
   unsigned long attribute_mask = CWBackPixmap;
   XSetWindowAttributes swa;
   memset(&swa, 0, sizeof(swa));
   swa.background_pixmap = None;
 
   ::Atom window_type;
   switch (params.type) {
     case Widget::InitParams::TYPE_MENU:
       swa.override_redirect = True;
-      attribute_mask |= CWOverrideRedirect;
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_MENU");
       break;
     case Widget::InitParams::TYPE_TOOLTIP:
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_TOOLTIP");
       break;
     case Widget::InitParams::TYPE_POPUP:
       swa.override_redirect = True;
-      attribute_mask |= CWOverrideRedirect;
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_NOTIFICATION");
       break;
+    case Widget::InitParams::TYPE_DRAG:
+      swa.override_redirect = True;
+      window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_DND");
+      break;
     default:
       window_type = atom_cache_.GetAtom("_NET_WM_WINDOW_TYPE_NORMAL");
       break;
   }
+  if (swa.override_redirect)
+    attribute_mask |= CWOverrideRedirect;
 
   bounds_ = params.bounds;
   xwindow_ = XCreateWindow(
       xdisplay_, x_root_window_,
       bounds_.x(), bounds_.y(),
       bounds_.width(), bounds_.height(),
       0,               // border width
       CopyFromParent,  // depth
       InputOutput,
       CopyFromParent,  // visual
@@ skipping 560 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme();
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views