Sandbox html_viewer on Linux.

mandoline/services/core_services/BUILD.gn

 # Copyright 2015 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.
 #
 # core_services should be thought of as a bundle of many of the services which
 # we ship with.
 
 import("//build/config/ui.gni")
 import("//mojo/public/mojo_application.gni")
 
@@ skipping 42 matching lines @@
   ]
 
   if (!is_android) {
     deps += [
       "//components/resource_provider:lib",
       "//components/view_manager:lib",
       "//mojo/services/network:lib",
     ]
   }
 
+  if (is_linux && !is_android) {
+    deps += [ "//components/font_service:lib" ]
+  }
+
   if (use_aura) {
     deps += [
       "//components/view_manager/public/cpp",
       "//mandoline/ui/omnibox:lib",
     ]
   }
 }