Provide startup resource numbering files for Mac and Windows.

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 231 matching lines @@
 }
 
 # TODO(aberent): Enable for other platforms once the build machines have
 #                Java on them (and hence can run the closure compiler).
 _strip_resource_files = is_android
 _js_minifier = "//third_party/closure_compiler/js_minify.py"
 
 grit_resource_id_file = "//tools/gritsettings/resource_ids"
 grit_info_script = "//tools/grit/grit_info.py"
 
+# TODO(asvitkine): Add predetermined ids files for other platforms.
 grit_predetermined_resource_ids_file = ""
-
-# TODO(asvitkine): Add platform-specific resource id file paths here.
-#                  http://crbug.com/692670
+if (is_mac) {
+  grit_predetermined_resource_ids_file =
+      "//tools/gritsettings/startup_resources_mac.txt"
+}
+if (is_win) {
+  grit_predetermined_resource_ids_file =
+      "//tools/gritsettings/startup_resources_win.txt"
+}
 
 template("grit") {
   assert(defined(invoker.source),
          "\"source\" must be defined for the grit template $target_name")
 
   if (defined(invoker.resource_ids)) {
     resource_ids = invoker.resource_ids
   } else {
     resource_ids = grit_resource_id_file
   }
@@ skipping 217 matching lines @@
     if (defined(invoker.configs)) {
       configs += invoker.configs
     }
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     output_name = grit_output_name
   }
 }