Re-land:

views/widget/drop_target_gtk.cc

Index: views/widget/drop_target_gtk.cc
===================================================================
--- views/widget/drop_target_gtk.cc	(revision 85284)
+++ views/widget/drop_target_gtk.cc	(working copy)
@@ -167,7 +167,7 @@
   if (!pending_view_) {
     // User isn't over a view, no drop can occur.
     static_cast<WidgetGtk*>(
-        helper_.root_view()->GetWidget())->ResetDropTarget();
+        helper_.root_view()->GetWidget()->native_widget())->ResetDropTarget();
     // WARNING: we've been deleted.
     return FALSE;
   }
@@ -246,7 +246,8 @@
   gtk_drag_finish(context, gdk_action != 0, (gdk_action & GDK_ACTION_MOVE),
                   time);
 
-  static_cast<WidgetGtk*>(helper_.root_view()->GetWidget())->ResetDropTarget();
+  static_cast<WidgetGtk*>(helper_.root_view()->GetWidget()->native_widget())->
+      ResetDropTarget();
   // WARNING: we've been deleted.
 }
 
@@ -264,9 +265,8 @@
                                    int formats,
                                    const std::set<GdkAtom>& custom_formats,
                                    guint time) {
-  GtkWidget* widget =
-      static_cast<WidgetGtk*>(helper_.root_view()->GetWidget())->
-      window_contents();
+  GtkWidget* widget = static_cast<WidgetGtk*>(helper_.root_view()->GetWidget()->
+      native_widget())->window_contents();
 
   const std::set<GdkAtom>& known_formats =
       data_provider().known_custom_formats();