Crash when accepting empty file string for upload

I can reliably reproduce the issue with the following simple QML scene:

    import QtQuick 2.0
    import com.canonical.Oxide 1.0

    WebView {
        width: 800
        height: 600

        url: "http://www.wufoo.com/html5/attributes/07-accept.html"

        filePicker: Item {
            Component.onCompleted: model.accept([""])
        }
    }

Here is the backtrace I’m getting:

#0 0x00007ffff5cabf79 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1 0x00007ffff5caf388 in __GI_abort () at abort.c:89
#2 0x00007fffcc64bc49 in base::debug::BreakDebugger() ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#3 0x00007fffcc672305 in logging::LogMessage::~LogMessage() ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#4 0x00007fffce8dc257 in content::RenderProcessHostImpl::ReceivedBadMessage() [clone .part.62] ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#5 0x00007fffce8dceb5 in content::RenderProcessHostImpl::ReceivedBadMessage() ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#6 0x00007fffce8ebcc7 in content::RenderViewHostImpl::OnMessageReceived(IPC::Message const&) [clone .part.128] ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#7 0x00007fffce8e1e91 in content::RenderProcessHostImpl::OnMessageReceived(IPC::Message const&) [clone .part.212] ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#8 0x00007fffccbe0382 in IPC::ChannelProxy::Context::OnDispatchMessage(IPC::Message const&) ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#9 0x00007fffcc679af3 in base::MessageLoop::RunTask(base::PendingTask const&) ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#10 0x00007fffcc67a0a1 in base::MessageLoop::DeferOrRunPendingTask(base::PendingTask const&) ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#11 0x00007fffcc67d255 in base::MessageLoop::DoWork() ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#12 0x00007fffcc5ef91a in oxide::qt::MessagePump::customEvent(QEvent*) ()
   from /home/osomon/dev/phablet/oxide/trunk/objdir-x64-release/out/chromium/Release/lib/libOxideQtCore.so.0
#13 0x00007ffff79c42ad in QObject::event (this=0xdcbbe0, e=<optimized out>) at kernel/qobject.cpp:1169
#14 0x00007ffff799befd in QCoreApplication::notify (this=<optimized out>, receiver=<optimized out>,
    event=<optimized out>) at kernel/qcoreapplication.cpp:943
#15 0x00007ffff799bc2d in QCoreApplication::notifyInternal (this=0x7fffffffda90, receiver=0xdcbbe0, event=event@entry=
    0x7fff8c09be10) at kernel/qcoreapplication.cpp:881
#16 0x00007ffff799de07 in sendEvent (event=0x7fff8c09be10, receiver=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:232
#17 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0,
    data=0x607100) at kernel/qcoreapplication.cpp:1485
#18 0x00007ffff799e433 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0,
    event_typ...