TaskScheduler: Set the current SequenceToken when a Task runs.

base/task_scheduler/scheduler_worker.cc

Index: base/task_scheduler/scheduler_worker.cc
diff --git a/base/task_scheduler/scheduler_worker.cc b/base/task_scheduler/scheduler_worker.cc
index 5a2a7d6a92b96272e1d148edeaec2c4a1782b672..822a582fffa2bc3d95955b4c7df9764aada5d01b 100644
--- a/base/task_scheduler/scheduler_worker.cc
+++ b/base/task_scheduler/scheduler_worker.cc
@@ -55,7 +55,7 @@ class SchedulerWorker::Thread : public PlatformThread::Delegate {
         continue;
       }
 
-      outer_->task_tracker_->RunTask(sequence->PeekTask());
+      outer_->task_tracker_->RunNextTaskInSequence(sequence.get());
 
       const bool sequence_became_empty = sequence->PopTask();