Fix GN bootstrap

BUG=none
R=brettw@chromium.org

Review-Url: https://codereview.chromium.org/2761733002 .
Cr-Original-Commit-Position: refs/heads/master@{#458129}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c5a76438bace67cd0438c0a072da270513a8bc9a
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index 75e2eb4..10dd512 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -472,6 +472,7 @@
       'base/task_scheduler/post_task.cc',
       'base/task_scheduler/priority_queue.cc',
       'base/task_scheduler/scheduler_lock_impl.cc',
+      'base/task_scheduler/scheduler_single_thread_task_runner_manager.cc',
       'base/task_scheduler/scheduler_worker.cc',
       'base/task_scheduler/scheduler_worker_pool_impl.cc',
       'base/task_scheduler/scheduler_worker_pool_params.cc',