DetachFromSequence in Timer::Stop()

base/timer/timer.cc

Index: base/timer/timer.cc
diff --git a/base/timer/timer.cc b/base/timer/timer.cc
index abcd70aefa1c31212945b01867e6c039c27a3b9e..1f6efcc7e3db704b60f2740f36e92b277734f1fd 100644
--- a/base/timer/timer.cc
+++ b/base/timer/timer.cc
@@ -99,8 +99,7 @@ Timer::Timer(const tracked_objects::Location& posted_from,
 }
 
 Timer::~Timer() {
-  // TODO(gab): Enable this once Stop() properly detaches from sequence.
-  // DCHECK(origin_sequence_checker_.CalledOnValidSequence());
+  DCHECK(origin_sequence_checker_.CalledOnValidSequence());
   AbandonAndStop();
 }
 
@@ -144,6 +143,10 @@ void Timer::Stop() {
   // DCHECK(origin_sequence_checker_.CalledOnValidSequence());
 
   is_running_ = false;
+
+  // It's safe to destroy or restart Timer on another sequence after Stop().

[danakj, 2017/06/06 20:07:12]

Did you intentionally do this before running the user_task_ destructors?

[gab, 2017/06/07 13:28:54]

Yes, see comment at the end of this method, it's not safe to access |this| after
destroying |user_task_| as it can own |this|.

+  origin_sequence_checker_.DetachFromSequence();
+
   if (!retain_user_task_)
     user_task_.Reset();
   // No more member accesses here: |this| could be deleted after freeing