mash: Crash on login restoring V1 app window with shelf model sync.

On ChromeOS ToT (or after #502992) with --login-manager:
(1) Pin Chrome Web Store to the shelf (from the app list).
(2) In the item's right-click context menu, select "Open as Window"
(3) Click the item to open a Chrome Web Store window.
(4a) Quit and re-run with --ash-enable-shelf-model-synchronization
(4b) Enable shelf model sync in about:flags and logout/login on device.
Expected: The session starts up just fine.
Actual: Crash attempting to restore the shelf item.

I'll look into why ChromeLauncherController::ShelfItemChanged is called, etc.
This should block enabling shelf model sync by default.

[71292:71292:0921/112934.661879:FATAL:shelf_controller.cc(215)] Check failed: index >= 0 (-1 vs. 0) No item found with the id: app_id:ahfgeienlihckogmohjhadlkjgocpleb, launch_id:
#0 0x7ffac746feec base::debug::StackTrace::StackTrace()
#1 0x7ffac7495a5c logging::LogMessage::~LogMessage()
#2 0x7ffac1f1c68c ash::ShelfController::UpdateShelfItem()
#3 0x7ffac21b2f98 ash::mojom::ShelfControllerStubDispatch::Accept()
#4 0x7ffac669ef1b mojo::InterfaceEndpointClient::HandleValidatedMessage()
#5 0x7ffac669e846 mojo::FilterChain::Accept()
#6 0x7ffac66a0235 mojo::InterfaceEndpointClient::HandleIncomingMessage()
#7 0x7ffac66aa3b4 mojo::internal::MultiplexRouter::ProcessIncomingMessage()
#8 0x7ffac66a9904 mojo::internal::MultiplexRouter::Accept()
#9 0x7ffac669e846 mojo::FilterChain::Accept()
#10 0x7ffac6699a45 mojo::Connector::ReadSingleMessage()
#11 0x7ffac669a531 mojo::Connector::ReadAllAvailableMessages()
#12 0x7ffac669a3d9 mojo::Connector::OnHandleReadyInternal()
#13 0x7ffac669ab85 mojo::SimpleWatcher::DiscardReadyState()
#14 0x7ffac6663e74 mojo::SimpleWatcher::OnHandleReady()
#15 0x7ffac66643b1 _ZN4base8internal7InvokerINS0_9BindStateIMN4mojo13SimpleWatcherEFvijRKNS3_18HandleSignalsStateEEJNS_7WeakPtrIS4_EEijS5_EEEFvvEE7RunImplIRKS9_RKNSt3__15tupleIJSB_ijS5_EEEJLm0ELm1ELm2ELm3EEEEvOT_OT0_NSI_16integer_sequenceImJXspT1_EEEE
#16 0x7ffac747077f base::debug::TaskAnnotator::RunTask()
#17 0x7ffac74a00f9 base::internal::IncomingTaskQueue::RunTask()
#18 0x7ffac74a23a3 base::MessageLoop::RunTask()
#19 0x7ffac74a2ace base::MessageLoop::DoWork()
#20 0x7ffac74a5369 base::MessagePumpLibevent::Run()
#21 0x7ffac74a1eb2 base::MessageLoop::Run()
#22 0x7ffac74d617f base::RunLoop::Run()
#23 0x5588700837da ChromeBrowserMainParts::MainMessageLoopRun()
#24 0x7ffac4914567 content::BrowserMainLoop::RunMainMessageLoopParts()
#25 0x7ffac4916f46 content::BrowserMainRunnerImpl::Run()
#26 0x7ffac490fdbf content::BrowserMain()
#27 0x7ffac518864c content::ContentMainRunnerImpl::Run()
#28 0x7ffac79ba09e service_manager::Main()
#29 0x7ffac5187024 content::ContentMain()
#30 0x55886f6641c8 ChromeMain
#31 0x7ffabb532f45 __libc_start_main
#32 0x55886f664004 <unknown>