[MD History] Vulcanize as part of GN build.

chrome/browser/resources/vulcanize.gni

 # Copyright 2017 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.
 
 template("vulcanize") {
   action(target_name) {
     script = "//chrome/browser/resources/vulcanize_gn.py"
 
     # Declare dependencies to all involved tools.
     inputs = [
@@ skipping 27 matching lines @@
       "--host",
       invoker.host,
       "--html_in_file",
       invoker.html_in_file,
       "--html_out_file",
       invoker.html_out_file,
       "--js_out_file",
       invoker.js_out_file,
       "--input",
       invoker.input,
-      "--insert_in_head",
-      invoker.insert_in_head,
       "--out_folder",
       rebase_path(target_gen_dir, root_build_dir),
       "--depfile",
       rebase_path(depfile, root_build_dir),
     ]
+
+    if (defined(invoker.excludes)) {
+      args += [ "--exclude" ]

[dpapad, 2017/02/09 19:14:04]

Nit: Would that work?

 args += [ "--exclude" ] + invoker.excludes

+      args += invoker.excludes
+    }
+
+    if (defined(invoker.insert_in_head)) {
+      args += [
+        "--insert_in_head",
+        invoker.insert_in_head,
+      ]
+    }
   }
 }