Fix empty resource IDs file in GN build.

build/secondary/tools/grit/grit_rule.gni

 # Copyright 2014 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.
 
 # Instantiate grit. This will produce a script target to run grit, and a
 # static library that compiles the .cc files.
 #
 # Parameters
 #
 #   source (required)
@@ skipping 264 matching lines @@
 
   grit_custom_target = target_name + "_grit"
   action(grit_custom_target) {
     script = "//tools/grit/grit.py"
     inputs = grit_inputs
     outputs = grit_outputs
     depfile = "$output_dir/${grit_output_name}.d"
 
     args = [
       "-i", source_path, "build",
-      "-f", resource_ids,
+    ]
+    if (resource_ids != "") {
+      args += [ "-f", resource_ids ]
+    }
+    args += [
       "-o", rebased_output_dir,
       "--depdir", ".",
       "--depfile", rebase_path(depfile, root_build_dir),
     ] + grit_defines
 
     # Add extra defines with -D flags.
     if (defined(invoker.defines)) {
       foreach (i, invoker.defines) {
         args += [ "-D", i ]
       }
@@ skipping 20 matching lines @@
     # target rather than this library.
     deps = [ ":$grit_custom_target" ]
     direct_dependent_configs = [ ":$grit_config" ]
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     output_name = grit_output_name
   }
 }