I've tried using SetTaskRunner on a RepeatingTimer (before doing anything else with it) and it's failing consistently as soon as timer triggers for the first time with the following stack trace:

Check failed: origin_sequence_checker_.CalledOnValidSequence().
Backtrace:
        base::debug::StackTrace::StackTrace [0x63E5C3B6+102] (C:\src\chrome\src\base\debug\stack_trace_win.cc:289)
        base::debug::StackTrace::StackTrace [0x63E5C33B+27] (C:\src\chrome\src\base\debug\stack_trace.cc:203)
        logging::LogMessage::~LogMessage [0x63EC0B24+148] (C:\src\chrome\src\base\logging.cc:591)
        base::internal::TimerBase::GetCurrentDelay [0x641052F9+201] (C:\src\chrome\src\base\timer\timer.cc:99)
        base::RepeatingTimer::RunUserTask [0x6410635A+74] (C:\src\chrome\src\base\timer\timer.cc:301)
        base::internal::TimerBase::RunScheduledTask [0x64105C25+293] (C:\src\chrome\src\base\timer\timer.cc:232)
        base::internal::BaseTimerTaskInternal::Run [0x64105A8C+60] (C:\src\chrome\src\base\timer\timer.cc:50)
        base::internal::FunctorTraits<void (base::internal::BaseTimerTaskInternal::*)() __attribute__((thiscall)),void>::Invoke<void (base::internal::BaseTimerTaskInternal::*)() __attribute__((thiscall)),base::internal::BaseTimerTaskInternal *> [0x64107DBC+28] (C:\src\chrome\src\base\bind_internal.h:516)
        base::internal::InvokeHelper<0,void>::MakeItSo<void (base::internal::BaseTimerTaskInternal::*)() __attribute__((thiscall)),base::internal::BaseTimerTaskInternal *> [0x64107D1F+79] (C:\src\chrome\src\base\bind_internal.h:616)
        base::internal::Invoker<base::internal::BindState<void (base::internal::BaseTimerTaskInternal::*)() __attribute__((thiscall)),base::internal::OwnedWrapper<base::internal::BaseTimerTaskInternal> >,void ()>::RunImpl<void (base::internal::BaseTimerTaskIntern [0x64107C75+85] (C:\src\chrome\src\base\bind_internal.h:689)
        base::internal::Invoker<base::internal::BindState<void (base::internal::BaseTimerTaskInternal::*)() __attribute__((thiscall)),base::internal::OwnedWrapper<base::internal::BaseTimerTaskInternal> >,void ()>::RunOnce [0x64107B24+84] (C:\src\chrome\src\base\bind_internal.h:658)
        base::OnceCallback<void ()>::Run [0x63DF6210+80] (C:\src\chrome\src\base\callback.h:100)
        base::debug::TaskAnnotator::RunTask [0x63E618B3+1075] (C:\src\chrome\src\base\debug\task_annotator.cc:101)
        base::internal::TaskTracker::RunOrSkipTask [0x640C8052+2690] (C:\src\chrome\src\base\task\task_scheduler\task_tracker.cc:654)
        base::internal::TaskTracker::RunAndPopNextTask [0x640C660E+638] (C:\src\chrome\src\base\task\task_scheduler\task_tracker.cc:508)
        base::internal::SchedulerWorker::RunWorker [0x640994C3+2147] (C:\src\chrome\src\base\task\task_scheduler\scheduler_worker.cc:331)
        base::internal::SchedulerWorker::RunBackgroundPooledWorker [0x64098A02+34] (C:\src\chrome\src\base\task\task_scheduler\scheduler_worker.cc:231)
        base::internal::SchedulerWorker::ThreadMain [0x640988FA+90] (C:\src\chrome\src\base\task\task_scheduler\scheduler_worker.cc:183)
        base::`anonymous namespace'::ThreadFunc [0x640DF446+310] (C:\src\chrome\src\base\threading\platform_thread_win.cc:102)
        BaseThreadInitThunk [0x774E62C4+36]
        RtlSubscribeWnfStateChangeNotification [0x77871F69+1081]
        RtlSubscribeWnfStateChangeNotification [0x77871F34+1028]


The problem seems to be (here TR=TaskRunner's Sequence):
- I create my timer on TR1, make it runs its tasks on TR2. My timer's origin_sequence_checker_ is not set at this point (as we detach in the timer's constructor).
- I call RepeatingTimer::Start on TR1, this calls TimerBase::StartInternal which set origin_sequence_checker_ to TR1.
- When my timer fires it calls RepeatingTimer::PostNewScheduledTask(GetCurrentDelay()) on TR2. This causes the call to origin_sequence_checker_.CalledOnValidSequence() in GetCurrentDelay to fail because we're on TR2 and origin_sequence_checker_ is associated with TR1.