Try to improve toolbar separator coloration for themed browser windows.

chrome/browser/ui/libgtkui/gtk_ui.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/libgtkui/gtk_ui.h"
 
 #include <math.h>
 #include <pango/pango.h>
 #include <X11/Xcursor/Xcursor.h>
 
@@ skipping 831 matching lines @@
   colors_[ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_BACKGROUND] =
       toolbar_color;
   colors_[ThemeProperties::COLOR_BOOKMARK_BAR_INSTRUCTIONS_TEXT] =
       GetFgColor("GtkToolbar#toolbar GtkLabel#label");
   // Separates the toolbar from the bookmark bar or butter bars.
   colors_[ThemeProperties::COLOR_TOOLBAR_BOTTOM_SEPARATOR] =
       toolbar_separator_horizontal;
   // Separates entries in the downloads bar.
   colors_[ThemeProperties::COLOR_TOOLBAR_VERTICAL_SEPARATOR] =
       toolbar_separator_vertical;
-  // Separates the bookmark bar from the web content.
-  colors_[ThemeProperties::COLOR_DETACHED_BOOKMARK_BAR_SEPARATOR] =
-      toolbar_separator_horizontal;
 
   // These colors represent the border drawn around tabs and between
   // the tabstrip and toolbar.  It's unclear if the selectors used are
   // correct, but they seem to give reasonable results.
   SkColor entry_border =
       GetBorderColor("#headerbar.header-bar.titlebar GtkEntry#entry");
   SkColor entry_inactive_border =
       GetBorderColor("#headerbar.header-bar.titlebar:backdrop GtkEntry#entry");
   // Unlike with toolbars, we always want a border around tabs, so let
   // ThemeService choose the border color if the theme doesn't provide one.
@@ skipping 229 matching lines @@
 
 float GtkUi::GetDeviceScaleFactor() const {
   return device_scale_factor_;
 }
 
 }  // namespace libgtkui
 
 views::LinuxUI* BuildGtkUi() {
   return new libgtkui::GtkUi;
 }