[scheduler]: Avoid waking up the scheduler to end long idle periods.

components/scheduler/child/null_idle_task_runner.cc

Index: components/scheduler/child/null_idle_task_runner.cc
diff --git a/components/scheduler/child/null_idle_task_runner.cc b/components/scheduler/child/null_idle_task_runner.cc
index 9d11e7c565f35095d7805ab1c26f184b36343e4d..a1f365b77f4c91fb93c74c6ffa1303c6b3799742 100644
--- a/components/scheduler/child/null_idle_task_runner.cc
+++ b/components/scheduler/child/null_idle_task_runner.cc
@@ -9,7 +9,7 @@ namespace scheduler {
 NullIdleTaskRunner::NullIdleTaskRunner()
     : SingleThreadIdleTaskRunner(nullptr,
                                  nullptr,
-                                 base::Callback<void(base::TimeTicks*)>(),
+                                 nullptr,
                                  "null.taskrunner") {
 }