[inspector_protocol] Allow overriding specific config values.

inspector_protocol.gni

 # Copyright 2016 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.
 
 # This template will generate inspector protocol source code. The code will
 # not be compiled, use get_target_outputs(<name>) to compile them.
 #
 # Inputs
 #
 #   config_file  (required)
@@ skipping 49 matching lines @@
 
     args = [
       "--jinja_dir",
       rebase_path("//third_party/", root_build_dir),  # jinja is in chromium's third_party
       "--output_base",
       rebase_path(invoker.out_dir, root_build_dir),
       "--config",
       rebase_path(invoker.config_file, root_build_dir),
     ]
 
+    if (defined(invoker.config_values)) {
+      foreach(value, invoker.config_values) {
+        args += [
+          "--config_value",
+          value,
+        ]
+      }
+    }
+
     outputs = get_path_info(rebase_path(invoker.outputs, ".", invoker.out_dir),
                             "abspath")
 
     forward_variables_from(invoker,
                            [
                              "visibility",
                              "deps",
                              "public_deps",
                            ])
   }
 }