Make docked panel always on top for Linux

chrome/browser/ui/gtk/panels/panel_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/gtk/panels/panel_gtk.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms.h>
 #include <X11/XF86keysym.h>
 
@@ skipping 298 matching lines @@
   gtk_container_add(GTK_CONTAINER(render_area_event_box_),
                     contents_expanded_);
   gtk_widget_show(render_area_event_box_);
   gtk_box_pack_end(GTK_BOX(window_vbox_), render_area_event_box_,
                    TRUE, TRUE, 0);
 
   gtk_container_add(GTK_CONTAINER(window_), window_container_);
   gtk_widget_show(window_container_);
 
   ConnectAccelerators();
+  SetPanelAlwaysOnTop(always_on_top_);
 }
 
 void PanelGtk::SetWindowCornerStyle(panel::CornerStyle corner_style) {
   corner_style_ = corner_style;
   UpdateWindowShape();
 }
 
 void PanelGtk::MinimizePanelBySystem() {
   gtk_window_iconify(window_);
 }
@@ skipping 670 matching lines @@
 
   NOTREACHED() << "Checking title height before window allocated";
   return 0;
 }
 
 bool PanelGtk::IsPanelAlwaysOnTop() const {
   return always_on_top_;
 }
 
 void PanelGtk::SetPanelAlwaysOnTop(bool on_top) {
-  if (always_on_top_ == on_top)
-    return;
   always_on_top_ = on_top;
 
   gtk_window_set_keep_above(window_, on_top);
 
   // Do not show an icon in the task bar for always-on-top windows.
   // Window operations such as close, minimize etc. can only be done
   // from the panel UI.
   gtk_window_set_skip_taskbar_hint(window_, on_top);
 
   // Show always-on-top windows on all the virtual desktops.
@@ skipping 163 matching lines @@
     default:
       NOTREACHED();
       return false;
   }
   return gtk_widget_get_visible(button->widget());
 }
 
 panel::CornerStyle GtkNativePanelTesting::GetWindowCornerStyle() const {
   return panel_gtk_->corner_style_;
 }