Manual regression range:
Good build : 63.0.3212.0 (Revision:500793).
Bad build : 63.0.3213.0 (Revision:501132).

Crash ID fd08bf14670f6977 (Local Crash ID: 9e2ef200-b7dd-4d0c-ba26-2ec68a765c86)

Note : Unable to narrow down the range using the per-revision bisect script since the original crash in not reproducible on continuous chrome builds, hence assigning the issue through CL.

Change Log URL : 
https://chromium.googlesource.com/chromium/src/+log/63.0.3212.0..63.0.3213.0?pretty=fuller&n=10000

Suspecting : r501081 ? from Change log

@alexmos : Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Note : 
1. In good builds, Audit process completes in few seconds without any issues but in bad build 'Auditing' takes more time to complete and browser crashes on clicking 'Cancel' button.
2. Issue is only reproducible on Windows 7 OS and the same issue is not reproducible on Win(8,10), Linux(14.04) and Mac(10.11.6, 10.12.3, 10.12.5) OS.

Thank you!

Adding RB Label as this is a recent Regression. Please remove if not required.

Providing Stack Trace for the Crash ID -- 841cd6b4ccb204bb.

Stack Trace ::
==============
Thread 0 (id: 3180) CRASHED [EXCEPTION_ACCESS_VIOLATION_READ @ 0x00000000 ] MAGIC SIGNATURE THREAD
Stack Quality100%Show frame trust levels
0x000007fed09965e7	(chrome_child.dll -render_widget.cc:2013 )	content::RenderWidget::OnOrientationChange()
0x000007fed09974a6	(chrome_child.dll -render_widget.cc:1331 )	content::RenderWidget::Resize(content::ResizeParams const &)
0x000007fed09f03ca	(chrome_child.dll -render_widget_screen_metrics_emulator.cc:138 )	content::RenderWidgetScreenMetricsEmulator::Apply()
0x000007fed099581f	(chrome_child.dll -render_widget.cc:777 )	content::RenderWidget::OnEnableDeviceEmulation(blink::WebDeviceEmulationParams const &)
0x000007fed098f26e	(chrome_child.dll -ipc_message_templates.h:146 )	IPC::MessageT<ViewMsg_EnableDeviceEmulation_Meta,std::tuple<blink::WebDeviceEmulationParams>,void>::Dispatch<content::RenderWidget,content::RenderWidget,void,void ( content::RenderWidget::*)(blink::WebDeviceEmulationParams const &)>(IPC::Message const *,content::RenderWidget *,content::RenderWidget *,void *,void ( content::RenderWidget::*)(blink::WebDeviceEmulationParams const &))
0x000007fed0995f73	(chrome_child.dll -render_widget.cc:635 )	content::RenderWidget::OnMessageReceived(IPC::Message const &)
0x000007fed09755e6	(chrome_child.dll -render_view_impl.cc:1197 )	content::RenderViewImpl::OnMessageReceived(IPC::Message const &)
0x000007fed0de511a	(chrome_child.dll -message_router.cc:56 )	IPC::MessageRouter::RouteMessage(IPC::Message const &)
0x000007fed0765836	(chrome_child.dll -child_thread_impl.cc:759 )	content::ChildThreadImpl::OnMessageReceived(IPC::Message const &)
0x000007fed014cc8b	(chrome_child.dll -ipc_channel_proxy.cc:320 )	IPC::ChannelProxy::Context::OnDispatchMessage(IPC::Message const &)
0x000007fed014bac1	(chrome_child.dll -bind_internal.h:349 )	base::internal::Invoker<base::internal::BindState<void ( IPC::ChannelProxy::Context::*)(IPC::Message const &),scoped_refptr<IPC::ChannelProxy::Context>,IPC::Message>,void >::RunImpl<void ( IPC::ChannelProxy::Context::*const &)(IPC::Message const &),std::tuple<scoped_refptr<IPC::ChannelProxy::Context>,IPC::Message> const &,0,1>(void ( IPC::ChannelProxy::Context::*const &)(IPC::Message const &),std::tuple<scoped_refptr<IPC::ChannelProxy::Context>,IPC::Message> const &,std::integer_sequence<unsigned __int64,0,1>)
0x000007feceb8c234	(chrome_child.dll -task_annotator.cc:61 )	base::debug::TaskAnnotator::RunTask(char const *,base::PendingTask *)
0x000007fecff2b9e0	(chrome_child.dll -task_queue_manager.cc:515 )	blink::scheduler::TaskQueueManager::ProcessTaskFromWorkQueue(blink::scheduler::internal::WorkQueue *,bool,blink::scheduler::LazyNow,base::TimeTicks *)
0x000007fecff2ab7f	(chrome_child.dll -task_queue_manager.cc:312 )	blink::scheduler::TaskQueueManager::DoWork(bool)
0x000007fecfcb0adc	(chrome_child.dll -bind_internal.h:297 )	base::internal::InvokeHelper<1,void>::MakeItSo<void ( media::VideoRendererImpl::*const &)(bool),base::WeakPtr<media::VideoRendererImpl> const &,bool>(void ( media::VideoRendererImpl::*const &)(bool),base::WeakPtr<media::VideoRendererImpl> const &,bool &&)
0x000007fecff296f7	(chrome_child.dll -bind_internal.h:349 )	base::internal::Invoker<base::internal::BindState<void ( blink::scheduler::TaskQueueManager::*)(bool),base::WeakPtr<blink::scheduler::TaskQueueManager>,bool>,void >::RunImpl<void ( blink::scheduler::TaskQueueManager::*const &)(bool),std::tuple<base::WeakPtr<blink::scheduler::TaskQueueManager>,bool> const &,0,1>(void ( blink::scheduler::TaskQueueManager::*const &)(bool),std::tuple<base::WeakPtr<blink::scheduler::TaskQueueManager>,bool> const &,std::integer_sequence<unsigned __int64,0,1>)
0x000007feceb8c234	(chrome_child.dll -task_annotator.cc:61 )	base::debug::TaskAnnotator::RunTask(char const *,base::PendingTask *)
0x000007feceb5a772	(chrome_child.dll -message_loop.cc:406 )	base::MessageLoop::RunTask(base::PendingTask *)
0x000007feceb5b102	(chrome_child.dll -message_loop.cc:524 )	base::MessageLoop::DoWork()
0x000007fecebab8f0	(chrome_child.dll -message_pump_default.cc:33 )	base::MessagePumpDefault::Run(base::MessagePump::Delegate *)
0x000007feceb72108	(chrome_child.dll -run_loop.cc:123 )	base::RunLoop::Run()
0x000007fed097755f	(chrome_child.dll -renderer_main.cc:220 )	content::RendererMain(content::MainFunctionParams const &)
0x000007fed00466be	(chrome_child.dll -content_main_runner.cc:425 )	content::RunNamedProcessTypeMain(std::basic_string<char,std::char_traits<char>,std::allocator<char> > const &,content::MainFunctionParams const &,content::ContentMainDelegate *)
0x000007fed0046509	(chrome_child.dll -content_main_runner.cc:703 )	content::ContentMainRunnerImpl::Run()
0x000007fed004d31d	(chrome_child.dll -main.cc:469 )	service_manager::Main(service_manager::MainParams const &)
0x000007fed0045d67	(chrome_child.dll -content_main.cc:19 )	content::ContentMain(content::ContentMainParams const &)
0x000007fecfb36bbd	(chrome_child.dll -chrome_main.cc:122 )	ChromeMain
0x000000013f89dd12	(chrome.exe -main_dll_loader_win.cc:199 )	MainDllLoader::Launch(HINSTANCE__ *,base::TimeTicks)
0x000000013f89cc9a	(chrome.exe -chrome_exe_main_win.cc:275 )	wWinMain
0x000000013f8cf302	(chrome.exe -exe_common.inl:253 )	__scrt_common_main_seh
0x774e59cc	(kernel32.dll + 0x000159cc )	BaseThreadInitThunk
0x7787b980	(ntdll.dll + 0x0002b980 )	RtlUserThreadStart

Thank You.

This is most likely related to  issue 764202 .  This is a browser crash looking at the video in the report; however, the crash in #3 is actually a renderer-side crash.  In any case, I'm investigating.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0b409c439665e83096af5cbc6ae6edc0bb67467b

commit 0b409c439665e83096af5cbc6ae6edc0bb67467b
Author: Alex Moshchuk <alexmos@chromium.org>
Date: Wed Sep 13 02:09:00 2017

Don't try to send screen orientation change events to provisional frames

DevTools audits trigger a ViewMsg_EnableDeviceEmulation on a pending
RenderFrameHost (see EmulationHandler::UpdateDeviceEmulationState, via
RenderFrameDevToolsAgentHost::AboutToNavigateRenderFrame), which is
processed by the frame's widget (WebViewFrameWidget) before the frame
commits.  In that state, RenderWidget::OnOrientationChange crashed,
because even though IsWebFrameWidget() was true for this widget,
WebViewFrameWidget::LocalRoot() returned null, since the frame
wasn't swapped into the tree yet.  The LocalRoot() was then used
to send screen orientation change events.

It doesn't make sense to fire events on a frame that hasn't committed
and isn't in the frame tree yet, so work around this by null-checking
LocalRoot().

Bug:  764202 ,  764206 
Change-Id: I26c1c9ce938abb7b18757b88356559a30aa08fec
Reviewed-on: https://chromium-review.googlesource.com/662904
Commit-Queue: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501517}
[modify] https://crrev.com/0b409c439665e83096af5cbc6ae6edc0bb67467b/content/browser/screen_orientation/screen_orientation_browsertest.cc
[modify] https://crrev.com/0b409c439665e83096af5cbc6ae6edc0bb67467b/content/renderer/render_widget.cc

 Issue 765546  has been merged into this issue.

The duped   Issue 765546   in comment#6 is still reproducible on latest M63-63.0.3218.0 on Ubuntu 14.04 with crash IDs:
 1515d025b0a6fdf6 , 07daa87863b80d2d 

Update : 
Retested above issue in latest chrome canary #63.0.3219.0 on Windows(7,8,10) & Linux(14.04 LTS) OS and issue seems fixed. Now 'Audits' process terminates on clicking 'Cancel' button without crashing the entire browser, hence adding TE-Verified labels.
Kindly review an attached screen cast.

Thank you!

Deleted: Canary_behavior.mp4 1.4 MB

	Canary_behavior.mp4 1.4 MB View Download

I've also tested this on Mac canary 63.0.3219.0, which includes the fix in r502651, and didn't see this crash anymore, so I'll mark this as fixed.