Move code that sets up the environment to run a task to TaskTracker::PerformRunTask().

base/task_scheduler/task_tracker_posix.h

Index: base/task_scheduler/task_tracker_posix.h
diff --git a/base/task_scheduler/task_tracker_posix.h b/base/task_scheduler/task_tracker_posix.h
index 040895317a8163b13417ab935dfade45cc74e2d6..a98b464cc24075aea3635249aa92c45ded4d0618 100644
--- a/base/task_scheduler/task_tracker_posix.h
+++ b/base/task_scheduler/task_tracker_posix.h
@@ -52,7 +52,8 @@ class BASE_EXPORT TaskTrackerPosix : public TaskTracker {
 
  private:
   // TaskTracker:
-  void PerformRunTask(std::unique_ptr<Task> task) override;
+  void PerformRunTask(std::unique_ptr<Task> task,
+                      const SequenceToken& sequence_token) override;
 
 #if DCHECK_IS_ON()
   bool IsPostingBlockShutdownTaskAfterShutdownAllowed() override;