diff -up chromium-60.0.3112.78/tools/gn/bootstrap/bootstrap.py.fixme chromium-60.0.3112.78/tools/gn/bootstrap/bootstrap.py
--- chromium-60.0.3112.78/tools/gn/bootstrap/bootstrap.py.fixme	2017-07-31 11:47:11.660774702 -0400
+++ chromium-60.0.3112.78/tools/gn/bootstrap/bootstrap.py	2017-07-31 11:47:32.859362600 -0400
@@ -487,6 +487,7 @@ def write_gn_ninja(path, root_gen_dir, o
       'base/sys_info.cc',
       'base/task_runner.cc',
       'base/task_scheduler/delayed_task_manager.cc',
+      'base/task_scheduler/environment_config.cc',
       'base/task_scheduler/post_task.cc',
       'base/task_scheduler/priority_queue.cc',
       'base/task_scheduler/scheduler_lock_impl.cc',