Chrome Version: ToT {#484301}
OS: Android

What steps will reproduce the problem?
(1) Add the flag --enable-blink-features=SetRootScroller, build Clank with DCHECKs on
(2) Visit https://bokand.github.io/rootscroller3.html

[6255:6359:0706/105506.972768:41685375626:FATAL:layer_tree_impl.cc(1676)] Check failed: scrollbar_ids.vertical == Layer::INVALID_ID (24 vs. -1)Existing scrollbar should have been unregistered.
#0 0x7f83e5b5668d base::debug::StackTrace::StackTrace()
#1 0x7f83e5b54ccc base::debug::StackTrace::StackTrace()
#2 0x7f83e5be4e4a logging::LogMessage::~LogMessage()
#3 0x7f83e577b692 cc::LayerTreeImpl::RegisterScrollbar()
#4 0x7f83e547394b cc::ScrollbarLayerImplBase::SetScrollElementId()
#5 0x7f83e54738a0 cc::ScrollbarLayerImplBase::PushPropertiesTo()
#6 0x7f83e54568e7 cc::PaintedOverlayScrollbarLayerImpl::PushPropertiesTo()
#7 0x7f83e580963b cc::PushLayerPropertiesInternal<>()
#8 0x7f83e5809316 cc::TreeSynchronizer::PushLayerProperties()
#9 0x7f83e57433b0 cc::LayerTreeHostImpl::ActivateSyncTree()
#10 0x7f83e57e9c74 cc::ProxyImpl::ScheduledActionActivateSyncTree()
#11 0x7f83e56314f7 cc::Scheduler::ProcessScheduledActions()
#12 0x7f83e5631ce8 cc::Scheduler::NotifyReadyToActivate()
#13 0x7f83e57e571a cc::ProxyImpl::NotifyReadyToActivate()
#14 0x7f83e573b14d cc::LayerTreeHostImpl::NotifyReadyToActivate()
#15 0x7f83e56bb521 cc::TileManager::CheckAndIssueSignals()
#16 0x7f83e550d6bd _ZN4base8internal13FunctorTraitsIMN2cc18LayerTreeFrameSinkEFvvEvE6InvokeIPS3_JEEEvS5_OT_DpOT0_
#17 0x7f83e550d604 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIRKMN2cc18LayerTreeFrameSinkEFvvEJPS5_EEEvOT_DpOT0_
#18 0x7f83e56d6595 _ZN4base8internal7InvokerINS0_9BindStateIMN2cc11TileManagerEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE7RunImplIRKS6_RKNSt3__15tupleIJS8_EEEJLm0EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEE
#19 0x7f83e56d64dc _ZN4base8internal7InvokerINS0_9BindStateIMN2cc11TileManagerEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE3RunEPNS0_13BindStateBaseE
#20 0x7f83eb0402dd _ZNKR4base8CallbackIFvvELNS_8internal8CopyModeE1ELNS2_10RepeatModeE1EE3RunEv
#21 0x7f83eb072673 cc::UniqueNotifier::Notify()
#22 0x7f83eb04107f _ZN4base8internal13FunctorTraitsIMN2cc21DelayedUniqueNotifierEFvvEvE6InvokeINS_7WeakPtrIS3_EEJEEEvS5_OT_DpOT0_
#23 0x7f83eb07285a _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIMN2cc14UniqueNotifierEFvvENS_7WeakPtrIS5_EEJEEEvOT_OT0_DpOT1_
#24 0x7f83eb0727f0 _ZN4base8internal7InvokerINS0_9BindStateIMN2cc14UniqueNotifierEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE7RunImplIS6_NSt3__15tupleIJS8_EEEJLm0EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEE
#25 0x7f83eb072749 _ZN4base8internal7InvokerINS0_9BindStateIMN2cc14UniqueNotifierEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#26 0x7f83e5b01fa1 _ZNO4base8CallbackIFvvELNS_8internal8CopyModeE0ELNS2_10RepeatModeE0EE3RunEv
#27 0x7f83e5b5b137 base::debug::TaskAnnotator::RunTask()
#28 0x7f83dbe80fd4 blink::scheduler::TaskQueueManager::ProcessTaskFromWorkQueue()
#29 0x7f83dbe7bf8a blink::scheduler::TaskQueueManager::DoWork()
#30 0x7f83dbe88e37 _ZN4base8internal13FunctorTraitsIMN5blink9scheduler16TaskQueueManagerEFvbEvE6InvokeIRKNS_7WeakPtrIS4_EEJRKbEEEvS6_OT_DpOT0_
#31 0x7f83dbe88d95 _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIRKMN5blink9scheduler16TaskQueueManagerEFvbERKNS_7WeakPtrIS6_EEJRKbEEEvOT_OT0_DpOT1_
#32 0x7f83dbe88d0d _ZN4base8internal7InvokerINS0_9BindStateIMN5blink9scheduler16TaskQueueManagerEFvbEJNS_7WeakPtrIS5_EEbEEEFvvEE7RunImplIRKS7_RKNSt3__15tupleIJS9_bEEEJLm0ELm1EEEEvOT_OT0_NS_13IndexSequenceIJXspT1_EEEE
#33 0x7f83dbe88c1c _ZN4base8internal7InvokerINS0_9BindStateIMN5blink9scheduler16TaskQueueManagerEFvbEJNS_7WeakPtrIS5_EEbEEEFvvEE3RunEPNS0_13BindStateBaseE
#34 0x7f83e5b01fa1 _ZNO4base8CallbackIFvvELNS_8internal8CopyModeE0ELNS2_10RepeatModeE0EE3RunEv
#35 0x7f83e5b5b137 base::debug::TaskAnnotator::RunTask()
#36 0x7f83e5c13bed base::MessageLoop::RunTask()
#37 0x7f83e5c13e77 base::MessageLoop::DeferOrRunPendingTask()
#38 0x7f83e5c14bfa base::MessageLoop::DoWork()
#39 0x7f83e5c1b458 base::MessagePumpDefault::Run()
#40 0x7f83e5c13514 base::MessageLoop::Run()
#41 0x7f83e5cc706d base::RunLoop::Run()
#42 0x7f83e5d92084 base::Thread::Run()
#43 0x7f83e5d92ca2 base::Thread::ThreadMain()
#44 0x7f83e5d73ed1 base::(anonymous namespace)::ThreadFunc()
#45 0x7f83eac6d184 start_thread
#46 0x7f83d81d8ffd clone

Note, I can repro this on linux using content_shell with the following flags:

./out/ChromeDebug/content_shell --single-process --enable-viewport --enable-features=OverlayScrollbar --enable-blink-features=SetRootScroller --enable-threaded-compositing --enable-prefer-compositing-to-lcd-text --enable-fixed-position-compositing ~/bokand.github.io/rootscroller3.html