Set the focus ring color to match the Gtk theme focus color.

chrome/common/gtk_util.cc

 // Copyright (c) 2009 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/common/gtk_util.h"
 
 #include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 
 #include <cstdarg>
@@ skipping 387 matching lines @@
       prefs->subpixel_rendering = RENDERER_PREFERENCES_SUBPIXEL_RENDERING_RGB;
     } else if (strcmp(rgba_style, "bgr") == 0) {
       prefs->subpixel_rendering = RENDERER_PREFERENCES_SUBPIXEL_RENDERING_BGR;
     } else if (strcmp(rgba_style, "vrgb") == 0) {
       prefs->subpixel_rendering = RENDERER_PREFERENCES_SUBPIXEL_RENDERING_VRGB;
     } else if (strcmp(rgba_style, "vbgr") == 0) {
       prefs->subpixel_rendering = RENDERER_PREFERENCES_SUBPIXEL_RENDERING_VBGR;
     }
   }
 
+  static GtkWidget* fixed = gtk_fixed_new();
+  GtkStyle* style = gtk_rc_get_style(fixed);
+  // base[SELECTED] seems more appropriate but in practice it is often too light
+  // to be easily visible.
+  GdkColor color = style->bg[GTK_STATE_SELECTED];
+  prefs->focus_ring_color_r = color.red / 257;
+  prefs->focus_ring_color_g = color.green / 257;
+  prefs->focus_ring_color_b = color.blue / 257;
+
   if (hint_style)
     g_free(hint_style);
   if (rgba_style)
     g_free(rgba_style);
 }
 
 gfx::Point ScreenPoint(GtkWidget* widget) {
   int x, y;
   gdk_display_get_pointer(gtk_widget_get_display(widget), NULL, &x, &y,
                           NULL);
@@ skipping 46 matching lines @@
 GdkColor AverageColors(GdkColor color_one, GdkColor color_two) {
   GdkColor average_color;
   average_color.pixel = 0;
   average_color.red = (color_one.red + color_two.red) / 2;
   average_color.green = (color_one.green + color_two.green) / 2;
   average_color.blue = (color_one.blue + color_two.blue) / 2;
   return average_color;
 }
 
 }  // namespace gtk_util