Modify guest_view_container_element.js to register guest view elements immediately rather than waiting for readystatechange.
Run python tools/perf/run_tests benchmarks.blink_perf_unittest.BlinkPerfTest.testBlinkPerfTracingMetricsForMeasurePageLoadTime -v --browser=cros-chrome --remote=[IP of dev chromebook]

[1:1:1015/102521.016122:FATAL:flat_tree_traversal.h(144)] Check failed: !node.NeedsDistributionRecalc(). 
#0 0x5bd50aca7ecf base::debug::StackTrace::StackTrace()
#1 0x5bd50ac01deb logging::LogMessage::~LogMessage()
#2 0x5bd50df80879 blink::FlatTreeTraversal::AssertPrecondition()
#3 0x5bd50df75ad8 blink::Node::IsInert()
#4 0x5bd50e121207 blink::LocalFrame::PropagateInertToChildFrames()
#5 0x5bd50e27275c blink::HTMLDialogElement::RemovedFrom()
#6 0x5bd50fb46da1 blink::ContainerNode::NotifyNodeRemoved()
#7 0x5bd50fb4737c blink::ContainerNode::RemoveChildren()
#8 0x5bd50fb43907 blink::CollectChildrenAndRemoveFromOldParent()
#9 0x5bd50fb434fb blink::ContainerNode::AppendChild()
#10 0x5bd50df72e08 blink::Node::appendChild()
#11 0x5bd50f63741b blink::V8Node::appendChildMethodCallbackForMainWorld()
#12 0x5bd50992bfee v8::internal::FunctionCallbackArguments::Call()
#13 0x5bd50992a603 v8::internal::(anonymous namespace)::HandleApiCallHelper<>()
#14 0x5bd509928967 v8::internal::Builtin_Impl_HandleApiCall()
#15 0x5bd5099283c5 v8::internal::Builtin_HandleApiCall()

[18633:18633:1015/102521.697353:FATAL:login_display_host_webui.cc(806)] Renderer crash on login window