Version: 57.0.2930.0
OS: Chrome OS

What steps will reproduce the problem?
(1) Open a PDF in the PDF viewer (e.g. https://graduateland.com/api/v2/users/jesper/cv)
(2) Use the trackpad to move the mouse in the viewer (or click within the viewer)
(3) Use the touchscreen to touch the viewer

It hits the following DCHECK:
[1:1:1123/151611:FATAL:Document.cpp(6038)] Check failed: !request.readOnly(). 

Here's the stacktrace:
#0 0x7fe1ae5db216 base::debug::StackTrace::StackTrace()
#1 0x7fe1ae5fd94e logging::LogMessage::~LogMessage()
#2 0x7fe1b1ec6b9d blink::Document::updateHoverActiveState()
#3 0x7fe1b256f68a blink::EventHandler::handleMouseMoveOrLeaveEvent()
#4 0x7fe1b256faf6 blink::EventHandler::handleMouseLeaveEvent()
#5 0x7fe1b1789c32 blink::PageWidgetEventHandler::handleMouseLeave()
#6 0x7fe1b17322ef blink::WebViewImpl::handleMouseLeave()
#7 0x7fe1b178a177 blink::PageWidgetDelegate::handleInputEvent()
#8 0x7fe1b17484eb blink::WebViewImpl::handleInputEvent()
#9 0x7fe1b372c7b1 content::RenderWidgetInputHandler::HandleInputEvent()
#10 0x7fe1b35f32b3 content::RenderWidget::OnMessageReceived()
#11 0x7fe1b35e034f content::RenderViewImpl::OnMessageReceived()
#12 0x7fe1b14d72e9 content::ChildThreadImpl::OnMessageReceived()
#13 0x7fe1b37275f3 content::InputEventFilter::HandleEventOnMainThread()
#14 0x7fe1b372a432 content::MainThreadEventQueue::DispatchInFlightEvent()
#15 0x7fe1b372aad6 content::MainThreadEventQueue::DispatchSingleEvent()
#16 0x7fe1ae69df38 base::debug::TaskAnnotator::RunTask()
#17 0x7fe1b169e2ff blink::scheduler::TaskQueueManager::ProcessTaskFromWorkQueue()
#18 0x7fe1b169efc9 blink::scheduler::TaskQueueManager::DoWork()
#19 0x7fe1ae69df38 base::debug::TaskAnnotator::RunTask()
#20 0x7fe1ae607082 base::MessageLoop::RunTask()
#21 0x7fe1ae60757e base::MessageLoop::DeferOrRunPendingTask()
#22 0x7fe1ae60b590 base::MessageLoop::DoWork()
#23 0x7fe1ae60bd93 base::MessagePumpDefault::Run()
#24 0x7fe1ae60869e base::MessageLoop::RunHandler()
#25 0x7fe1ae639bf8 base::RunLoop::Run()
#26 0x7fe1b3602dd2 content::RendererMain()
#27 0x7fe1ae0270af content::RunZygote()
#28 0x7fe1ae027415 content::RunNamedProcessTypeMain()
#29 0x7fe1ae0274d5 content::ContentMainRunnerImpl::Run()
#30 0x7fe1ae026759 content::ContentMain()
#31 0x7fe1abfc47b6 ChromeMain
#32 0x7fe1a9978fb6 __libc_start_main
#33 0x7fe1abfc4604 <unknown>