Fix bug 139829: Panels [Linux]: Dark titlebar theme only works with Classic theme, not with GTK+ th…

chrome/browser/ui/panels/panel_browser_window_gtk.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 "chrome/browser/ui/panels/panel_browser_window_gtk.h"
 
 #include "base/bind.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window.h"
@@ skipping 125 matching lines @@
 PanelBrowserTitlebarGtk* PanelBrowserWindowGtk::GetPanelTitlebar() const {
   return static_cast<PanelBrowserTitlebarGtk*>(titlebar());
 }
 
 bool PanelBrowserWindowGtk::UsingDefaultTheme() const {
   // No theme is provided for attention painting.
   if (paint_state_ == PAINT_FOR_ATTENTION)
     return true;
 
   GtkThemeService* theme_provider = GtkThemeService::GetFrom(panel_->profile());
-  return theme_provider->UsingDefaultTheme();
+  return theme_provider->UsingDefaultTheme() ||
+         theme_provider->UsingNativeTheme();
 }
 
 bool PanelBrowserWindowGtk::GetWindowEdge(int x, int y, GdkWindowEdge* edge) {
   // Only detect the window edge when panels can be resized by the user.
   // This method is used by the base class to detect when the cursor has
   // hit the window edge in order to change the cursor to a resize cursor
   // and to detect when to initiate a resize drag.
   panel::Resizability resizability = panel_->CanResizeByMouse();
   if (panel::NOT_RESIZABLE == resizability)
     return false;
@@ skipping 601 matching lines @@
       break;
     case panel::RESTORE_BUTTON:
       button = titlebar->restore_button();
       break;
     default:
       NOTREACHED();
       return false;
   }
   return gtk_widget_get_visible(button->widget());
 }