Maintaing the proper order of initialization WeakPtrFactory

base/task/cancelable_task_tracker.h

Index: base/task/cancelable_task_tracker.h
diff --git a/base/task/cancelable_task_tracker.h b/base/task/cancelable_task_tracker.h
index 3d849bf14929bf297472f22aa2a4239b8a958c68..b8a8b70e333922b41d5e7019070f09e18a6a12e4 100644
--- a/base/task/cancelable_task_tracker.h
+++ b/base/task/cancelable_task_tracker.h
@@ -126,11 +126,12 @@ class BASE_EXPORT CancelableTaskTracker {
   void Untrack(TaskId id);
 
   base::hash_map<TaskId, base::CancellationFlag*> task_flags_;
-  base::WeakPtrFactory<CancelableTaskTracker> weak_factory_;
 
   TaskId next_id_;
   base::ThreadChecker thread_checker_;
 
+  base::WeakPtrFactory<CancelableTaskTracker> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(CancelableTaskTracker);
 };