Fix RTL and complex script title in print preview header/footer.

ui/gfx/platform_font_pango.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 "ui/gfx/platform_font_pango.h"
 
 #include <algorithm>
 #include <fontconfig/fontconfig.h>
 #include <map>
 #include <pango/pango.h>
@@ skipping 83 matching lines @@
 // pango_font_description_from_string()) for the default UI font.
 std::string GetDefaultFont() {
 #if defined(USE_WAYLAND) || !defined(TOOLKIT_USES_GTK)
 #if defined(OS_CHROMEOS)
   return l10n_util::GetStringUTF8(IDS_UI_FONT_FAMILY_CROS);
 #else
   return "sans 10";
 #endif    // defined(OS_CHROMEOS)
 #else
   GtkSettings* settings = gtk_settings_get_default();
+  if (settings == NULL) {  // Probably caused by sandbox, give a default.
+    return "sans 10";
+  }
 
   gchar* font_name = NULL;
   g_object_get(settings, "gtk-font-name", &font_name, NULL);
 
   // Temporary CHECK for helping track down
   // http://code.google.com/p/chromium/issues/detail?id=12530
   CHECK(font_name) << " Unable to get gtk-font-name for default font.";
 
   std::string default_font = std::string(font_name);
   g_free(font_name);
@@ skipping 312 matching lines @@
   return new PlatformFontPango(native_font);
 }
 
 // static
 PlatformFont* PlatformFont::CreateFromNameAndSize(const std::string& font_name,
                                                   int font_size) {
   return new PlatformFontPango(font_name, font_size);
 }
 
 }  // namespace gfx