▶ CRASH [expected OK] /websockets/unload-a-document/001.html?default
  │ 
  │ called `Option::unwrap()` on a `None` value (thread Script(1,1), at components/script/dom/window.rs:560)
  │    0: servoshell::backtrace::print
  │    1: servoshell::panic_hook::panic_hook
  │    2: std::panicking::rust_panic_with_hook
  │    3: std::panicking::begin_panic_handler::{{closure}}
  │    4: std::sys::backtrace::__rust_end_short_backtrace
  │    5: __rustc::rust_begin_unwind
  │    6: core::panicking::panic_fmt
  │    7: core::panicking::panic
  │    8: core::option::unwrap_failed
  │    9: <script::dom::window::Window as script_bindings::codegen::GenericBindings::WindowBinding::Window_Binding::WindowMethods<script::dom::bindings::codegen::DomTypeHolder::DomTypeHolder>>::Frames
  │   10: script::dom::storage::Storage::webview_id
  │   11: <script::dom::storage::Storage as script_bindings::codegen::GenericBindings::StorageBinding::Storage_Binding::StorageMethods<script::dom::bindings::codegen::DomTypeHolder::DomTypeHolder>>::RemoveItem
  │   12: script_bindings::codegen::GenericBindings::StorageBinding::Storage_Binding::delete::{{closure}}
  │   13: mozjs::panic::wrap_panic
  │   14: script_bindings::codegen::GenericBindings::StorageBinding::Storage_Binding::delete
  │   15: _ZNK22ForwardingProxyHandler7delete_EP9JSContextN2JS6HandleIP8JSObjectEENS3_INS2_11PropertyKeyEEERNS2_14ObjectOpResultE
  │   16: _ZL20proxy_DeletePropertyP9JSContextN2JS6HandleIP8JSObjectEENS2_INS1_11PropertyKeyEEERNS1_14ObjectOpResultE
  │   17: _ZN2js16DelElemOperationILb0EEEbP9JSContextN2JS6HandleINS3_5ValueEEES6_Pb
  │   18: _ZN2js9InterpretEP9JSContextRNS_8RunStateE
  │   19: _ZN2js9RunScriptEP9JSContextRNS_8RunStateE
  │   20: _ZN2js23InternalCallOrConstructEP9JSContextRKN2JS8CallArgsENS_14MaybeConstructENS_10CallReasonE
  │   21: _ZN2js4CallEP9JSContextN2JS6HandleINS2_5ValueEEES5_RKNS_13AnyInvokeArgsENS2_13MutableHandleIS4_EENS_10CallReasonE
  │   22: _ZN2js8fun_callEP9JSContextjPN2JS5ValueE
  │   23: _ZN2js23InternalCallOrConstructEP9JSContextRKN2JS8CallArgsENS_14MaybeConstructENS_10CallReasonE
  │   24: _ZN2js9InterpretEP9JSContextRNS_8RunStateE
  │   25: _ZN2js9RunScriptEP9JSContextRNS_8RunStateE
  │   26: _ZN2js23InternalCallOrConstructEP9JSContextRKN2JS8CallArgsENS_14MaybeConstructENS_10CallReasonE
  │   27: _ZN2js4CallEP9JSContextN2JS6HandleINS2_5ValueEEES5_RKNS_13AnyInvokeArgsENS2_13MutableHandleIS4_EENS_10CallReasonE
  │   28: _ZN2js9fun_applyEP9JSContextjPN2JS5ValueE
  │   29: _ZN2js23InternalCallOrConstructEP9JSContextRKN2JS8CallArgsENS_14MaybeConstructENS_10CallReasonE
  │   30: _ZN2js9InterpretEP9JSContextRNS_8RunStateE
  │   31: _ZN2js9RunScriptEP9JSContextRNS_8RunStateE
  │   32: _ZN2js23InternalCallOrConstructEP9JSContextRKN2JS8CallArgsENS_14MaybeConstructENS_10CallReasonE
  │   33: _ZN2js4CallEP9JSContextN2JS6HandleINS2_5ValueEEES5_RKNS_13AnyInvokeArgsENS2_13MutableHandleIS4_EENS_10CallReasonE
  │   34: _ZN2JS4CallEP9JSContextNS_6HandleINS_5ValueEEES4_RKNS_16HandleValueArrayENS_13MutableHandleIS3_EE
  │   35: script_bindings::codegen::GenericBindings::FunctionBinding::Function<D>::Call
  │   36: script_bindings::codegen::GenericBindings::FunctionBinding::Function<D>::Call_
  │   37: script::timers::OneshotTimerCallback::invoke
  │   38: script::timers::OneshotTimers::fire_timer
  │   39: <script::timers::TimerListener::handle::timer_event<F> as script::task::TaskOnce>::run_once
  │   40: <T as script::task::TaskBox>::run_box
  │   41: script::script_thread::ScriptThread::handle_msg_from_script
  │   42: script::script_thread::ScriptThread::handle_msgs::{{closure}}
  │   43: script::script_thread::ScriptThread::profile_event
  │   44: script::script_thread::ScriptThread::handle_msgs
  │   45: script::script_thread::ScriptThread::start
  │   46: std::sys::backtrace::__rust_begin_short_backtrace
  │   47: core::ops::function::FnOnce::call_once{{vtable.shim}}
  │   48: std::sys::pal::unix::thread::Thread::new::thread_start
  │   49: <unknown>
  └   50: <unknown>