Version: ToT (55.0.2867.0 unknown (64-bit))

Steps to reproduce:
1. Open the MR dialog, choose "Cast desktop" as your cast mode
2. Choose a sink. Press cancel on the two popups asking for permission to mirror desktop.

This occurs infrequently, less than 10% of the time. I was not able to repro on Stable, but that could be due to the infrequency of the bug occurring.


I get the following error with the crash, so it seems to be Linux-specific:

[25858:25858:0921/094303:ERROR:desktop_window_tree_host_x11.cc(1124)] Not implemented reached in virtual void views::DesktopWindowTreeHostX11::InitModalType(ui::ModalType)

../../third_party/webrtc/modules/desktop_capture/x11/x_error_trap.cc:30: int webrtc::(anonymous namespace)::XServerErrorHandler(Display *, XErrorEvent *): Assertion `g_xserver_error_trap_enabled' failed.