The following layout test crashes on Windows: inspector-protocol/debugger/pause-on-assert.html This appears to be a crash in a destructor in the JavaScriptCore library. The stack trace is as follows: vrfcore.dll!_VerifierStopMessageEx() Unknown vfbasics.dll!_AVrfpThreadFunctionExceptionFilter@4() Unknown vfbasics.dll!_AVrfpStandardThreadFunction@4() Unknown vfbasics.dll!@_EH4_CallFilterFunc@8() Unknown ntdll.dll!ExecuteHandler2@20() Unknown ntdll.dll!ExecuteHandler@20() Unknown ntdll.dll!_KiUserExceptionDispatcher@8() Unknown JavaScriptCore_debug.dll!WTF::HashTable<JSC::CodeBlock *,JSC::CodeBlock *,WTF::IdentityExtractor,WTF::PtrHash<JSC::CodeBlock *>,WTF::HashTraits<JSC::CodeBlock *>,WTF::HashTraits<JSC::CodeBlock *> >::size() Line 374 C++ JavaScriptCore_debug.dll!JSC::HandleNode::handleSet() Line 163 C++ > JavaScriptCore_debug.dll!JSC::HandleSet::heapFor(JSC::JSValue * handle) Line 108 C++ JavaScriptCore_debug.dll!JSC::Strong<JSC::ExecutableBase>::clear() Line 126 C++ JavaScriptCore_debug.dll!JSC::Strong<JSC::JSObject>::~Strong<JSC::JSObject>() Line 83 C++ [External Code] JavaScriptCore_debug.dll!WTF::HashTable<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> > >,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashMap<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject>,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> >,WTF::HashTraits<JSC::Strong<JSC::JSObject> > >::KeyValuePairTraits,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> > >::deallocateTable(WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> > * table, int size) Line 1079 C++ JavaScriptCore_debug.dll!WTF::HashTable<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> > >,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashMap<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject>,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> >,WTF::HashTraits<JSC::Strong<JSC::JSObject> > >::KeyValuePairTraits,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> > >::~HashTable<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject> > >,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashMap<std::pair<JSC::ExecState *,JSC::JSGlobalObject *>,JSC::Strong<JSC::JSObject>,WTF::PairHash<JSC::ExecState *,JSC::JSGlobalObject *>,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> >,WTF::HashTraits<JSC::Strong<JSC::JSObject> > >::KeyValuePairTraits,WTF::HashTraits<std::pair<JSC::ExecState *,JSC::JSGlobalObject *> > >() Line 353 C++ [External Code] JavaScriptCore_debug.dll!Inspector::InjectedScriptHost::~InjectedScriptHost() Line 39 C++ [External Code] JavaScriptCore_debug.dll!WTF::RefCounted<JSC::Profile>::deref() Line 146 C++ JavaScriptCore_debug.dll!WTF::derefIfNotNull<JSC::Profile>(JSC::Profile * ptr) Line 43 C++ JavaScriptCore_debug.dll!WTF::PassRefPtr<Inspector::Protocol::Runtime::StructureDescription>::~PassRefPtr<Inspector::Protocol::Runtime::StructureDescription>() Line 58 C++ JavaScriptCore_debug.dll!Inspector::InjectedScriptManager::~InjectedScriptManager() Line 58 C++ WebKit_debug.dll!WebCore::WebInjectedScriptManager::~WebInjectedScriptManager() Line 42 C++ [External Code] WebKit_debug.dll!WebCore::WorkerInspectorController::~WorkerInspectorController() Line 115 C++ [External Code] WebKit_debug.dll!WebCore::WorkerGlobalScope::~WorkerGlobalScope() Line 92 C++ WebKit_debug.dll!WebCore::DedicatedWorkerGlobalScope::~DedicatedWorkerGlobalScope() Line 56 C++ [External Code] WebKit_debug.dll!WTF::RefCounted<WebCore::WorkerGlobalScope>::deref() Line 146 C++ WebKit_debug.dll!WTF::derefIfNotNull<WebCore::WorkerGlobalScope>(WebCore::WorkerGlobalScope * ptr) Line 43 C++ WebKit_debug.dll!WTF::PassRefPtr<WebCore::WorkerGlobalScope>::~PassRefPtr<WebCore::WorkerGlobalScope>() Line 58 C++ WebKit_debug.dll!WTF::RefPtr<WebCore::WorkerGlobalScope>::operator=(WebCore::WorkerGlobalScope * optr) Line 141 C++ WebKit_debug.dll!WebCore::WorkerThread::workerThread() Line 179 C++ WebKit_debug.dll!WebCore::WorkerThread::workerThreadStart(void * thread) Line 138 C++ WTF_debug.dll!WTF::createThread::__l3::<lambda>() Line 81 C++ [External Code] WTF_debug.dll!WTF::threadEntryPoint(void * contextData) Line 59 C++ WTF_debug.dll!WTF::wtfThreadEntryPoint(void * param) Line 203 C++ [External Code]