OS: Chrome OS

What steps will reproduce the problem?
(1) Signin as Guest on a Chrome OS device
(2) go to chrome://policy

What is the expected result?
Policy page

What happens instead?
Chrome crashes here: https://cs.chromium.org/chromium/src/chrome/browser/policy/policy_conversions.cc?rcl=bd86e09382181645e7107433dff0f7da9c01d834&l=170

Regression CL: https://chromium-review.googlesource.com/c/chromium/src/+/1108922

Stack trace:
#0 0x7f0d477f488c base::debug::StackTrace::StackTrace()
#1 0x7f0d477f4381 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7f0d3aa780c0 <unknown>
#3 0x5582e857cb41 policy::GetAllPolicyValuesAsDictionary()
#4 0x5582e96f7bf5 PolicyUIHandler::SendPolicyValues()
#5 0x5582e96f7767 PolicyUIHandler::HandleInitialized()
#6 0x7f0d44e1f4a8 content::WebUIImpl::ProcessWebUIMessage()
#7 0x7f0d44e1e59c _ZN3IPC8MessageTI27FrameHostMsg_WebUISend_MetaNSt3__15tupleIJNS2_12basic_stringIcNS2_11char_traitsIcEENS2_9allocatorIcEEEEN4base9ListValueEEEEvE8DispatchIN7content9WebUIImplESG_NSF_15RenderFrameHostEMSG_FvPSH_RKS9_RKSB_EEEbPKNS_7MessageEPT_PT0_PT1_T2_
#8 0x7f0d44e1e4dc content::WebUIImpl::OnMessageReceived()
#9 0x7f0d44dd9424 content::WebContentsImpl::OnMessageReceived()
#10 0x7f0d44a8fc04 content::RenderFrameHostImpl::OnMessageReceived()
#11 0x7f0d44c983ab content::RenderProcessHostImpl::OnMessageReceived()
#12 0x7f0d468f3b81 IPC::ChannelProxy::Context::OnDispatchMessage()
#13 0x7f0d468f66ab _ZN4base8internal7InvokerINS0_9BindStateIMN3IPC12ChannelProxy7ContextEFvRKNS3_7MessageEEJ13scoped_refptrIS5_ES6_EEEFvvEE3RunEPNS0_13BindStateBaseE
#14 0x7f0d47727215 base::debug::TaskAnnotator::RunTask()
#15 0x7f0d47750789 base::internal::IncomingTaskQueue::RunTask()
#16 0x7f0d4775412b base::MessageLoop::RunTask()
#17 0x7f0d477544ba base::MessageLoop::DeferOrRunPendingTask()
#18 0x7f0d4775471c base::MessageLoop::DoWork()
#19 0x7f0d478148c9 base::MessagePumpLibevent::Run()
#20 0x7f0d47753b14 base::MessageLoop::Run()
#21 0x7f0d47786a69 base::RunLoop::Run()
#22 0x5582e84f342b ChromeBrowserMainParts::MainMessageLoopRun()
#23 0x7f0d4490d9d7 content::BrowserMainLoop::RunMainMessageLoopParts()
#24 0x7f0d449105e6 content::BrowserMainRunnerImpl::Run()
#25 0x7f0d44909bc4 content::BrowserMain()
#26 0x7f0d4534c71e content::RunBrowserProcessMain()
#27 0x7f0d4534d5f3 content::ContentMainRunnerImpl::Run()
#28 0x7f0d47aa798c service_manager::Main()
#29 0x7f0d4534b824 content::ContentMain()
#30 0x5582e79810d3 ChromeMain
#31 0x7f0d393b32b1 __libc_start_main
#32 0x5582e7980f4a _start