TaskScheduler: Add FlushForTesting().

base/task_scheduler/task_scheduler_impl.cc

Index: base/task_scheduler/task_scheduler_impl.cc
diff --git a/base/task_scheduler/task_scheduler_impl.cc b/base/task_scheduler/task_scheduler_impl.cc
index d93c62023e8107b963f6747501dd253fd0da1173..d40fa1b76859ef2434dd6629cef22717857dc8f0 100644
--- a/base/task_scheduler/task_scheduler_impl.cc
+++ b/base/task_scheduler/task_scheduler_impl.cc
@@ -57,6 +57,10 @@ void TaskSchedulerImpl::Shutdown() {
   task_tracker_.Shutdown();
 }
 
+void TaskSchedulerImpl::FlushForTesting() {
+  task_tracker_.FlushForTesting();

[danakj, 2016/09/23 20:51:41]

This is production code calling a ForTesting method. You need to not use
ForTesting in the name of the task tracker's method or you're leaving a
presubmit bomb for everyone else who touches this file.

[fdoray, 2016/09/23 21:09:46]

Done.

+}
+
 void TaskSchedulerImpl::JoinForTesting() {
 #if DCHECK_IS_ON()
   DCHECK(!join_for_testing_returned_.IsSet());