Fix for dropdown flicker....

views/widget/widget_gtk.cc

 // Copyright (c) 2010 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 "views/widget/widget_gtk.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
 #include <X11/extensions/shape.h>
 
@@ skipping 883 matching lines @@
   // reset the shape in this method regardless of whether the size changed.
   gfx::Size new_size(allocation->width, allocation->height);
   if (new_size == size_)
     return;
   size_ = new_size;
   root_view_->SetBounds(0, 0, allocation->width, allocation->height);
   root_view_->SchedulePaint();
 }
 
 gboolean WidgetGtk::OnPaint(GtkWidget* widget, GdkEventExpose* event) {
-  if (transparent_) {
+  if (transparent_ && type_ == TYPE_CHILD) {
     // Clear the background before drawing any view and native components.
     DrawTransparentBackground(widget, event);
   }
   root_view_->OnPaint(event);
   return false;  // False indicates other widgets should get the event as well.
 }
 
 void WidgetGtk::OnDragDataGet(GtkWidget* widget,
                               GdkDragContext* context,
                               GtkSelectionData* data,
@@ skipping 614 matching lines @@
     GtkWindow* window = GTK_WINDOW(element->data);
     DCHECK(window);
     RootView *root_view = FindRootView(window);
     if (root_view)
       root_view->NotifyLocaleChanged();
   }
   g_list_free(window_list);
 }
 
 }  // namespace views