Version: r400855
OS: Windows Server 2012, likely other windows versions.

What steps will reproduce the problem?
1. Run chrome with --enable-cloud-print-proxy, go to chrome://devices and set up the XPS printer with cloud print.
2. Go to example.com and print to the XPS printer via cloud print. Save the XPS document.

What is the expected output?
Printed document is saved without error.

What do you see instead?
An "Abort, Retry, Ignore" dialog box pops up after saving the file. Attaching to the service utility process using windbg shows the following stack trace:
ntdll!NtRaiseHardError+0xa
USER32!ServiceMessageBox+0x1b2
USER32!MessageBoxWorker+0x1b8
USER32!MessageBoxTimeoutW+0xba
USER32!MessageBoxW+0x4e
ucrtbased!__acrt_MessageBoxW+0x57
ucrtbased!__crt_char_traits<wchar_t>::message_box<HWND__ * __ptr64,wchar_t const * __ptr64 const & __ptr64,wchar_t const * __ptr64 const & __ptr64,unsigned int const & __ptr64>+0x3d
ucrtbased!common_show_message_box<wchar_t>+0x1b4
ucrtbased!__acrt_show_wide_message_box+0x27
ucrtbased!__crt_char_traits<wchar_t>::show_message_box<wchar_t (& __ptr64)[576],wchar_t const * __ptr64,long>+0x2d
ucrtbased!common_assert_to_message_box<wchar_t>+0x9e
ucrtbased!common_assert<wchar_t>+0x83
ucrtbased!_wassert+0x2f
chrome_4c46a50000!FXJS_Initialize+0x67
chrome_4c46a50000!IJS_Runtime::Initialize+0x1b
chrome_4c46a50000!FPDF_InitLibraryWithConfig+0xf2
chrome_4c46a50000!chrome_pdf::InitializeSDK+0x37
chrome_4c46a50000!chrome_pdf::RenderPDFPageToDC+0x3c
chrome_4c46a50000!printing::PrintingHandler::RenderPdfPageToMetafile+0x29d
chrome_4c46a50000!printing::PrintingHandler::OnRenderPDFPagesToMetafileGetPage+0x8b
chrome_4c46a50000!base::DispatchToMethodImpl<printing::PrintingHandler * __ptr64,void (__cdecl printing::PrintingHandler::*)(int,base::SharedMemoryHandle) __ptr64,int,base::SharedMemoryHandle,0,1>+0x6f
chrome_4c46a50000!base::DispatchToMethod<printing::PrintingHandler * __ptr64,void (__cdecl printing::PrintingHandler::*)(int,base::SharedMemoryHandle) __ptr64,int,base::SharedMemoryHandle>+0x2d
chrome_4c46a50000!IPC::DispatchToMethod<printing::PrintingHandler,void (__cdecl printing::PrintingHandler::*)(int,base::SharedMemoryHandle) __ptr64,void,std::tuple<int,base::SharedMemoryHandle> >+0x2c
chrome_4c46a50000!IPC::MessageT<ChromeUtilityMsg_RenderPDFPagesToMetafiles_GetPage_Meta,std::tuple<int,base::SharedMemoryHandle>,void>::Dispatch<printing::PrintingHandler,printing::PrintingHandler,void,void (__cdecl printing::PrintingHandler::*)(int,base::SharedMemoryHandle) __ptr64>+0x111
chrome_4c46a50000!printing::PrintingHandler::OnMessageReceived+0x16f
chrome_4c46a50000!ChromeContentUtilityClient::OnMessageReceived+0x2fb
content!content::UtilityThreadImpl::OnControlMessageReceived+0x3d
content!content::ChildThreadImpl::OnMessageReceived+0x705
ipc!IPC::ChannelProxy::Context::OnDispatchMessage+0x92
ipc!base::internal::RunnableAdapter<void (__cdecl IPC::ChannelProxy::Context::*)(IPC::Message const & __ptr64) __ptr64>::Run<scoped_refptr<IPC::ChannelProxy::Context> const & __ptr64,IPC::Message const & __ptr64>+0x4a


Stack frame in chrome points to:
void FXJS_Initialize(unsigned int embedderDataSlot, v8::Isolate* pIsolate) {
  if (g_isolate) {
    ASSERT(g_embedderDataSlot == embedderDataSlot);
    ASSERT(g_isolate == pIsolate);    <<<<======= HERE!!!!
    return;
  }
  g_embedderDataSlot = embedderDataSlot;
  g_isolate = pIsolate;
}