Chrome Version       : 54.0.2840.24
OS Version           : 8743.25.0
Device               :  Elm

What steps will reproduce the problem?
1. Sign in @gmail.com as secondary account
2.
3.

What is the expected result?

What happens instead of that?

Device is quite sluggish.
Possibly related, file:///var/log/ui/ui.LATEST is filling up with messages like:

[1:1:0927/150632:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150632:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150632:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150633:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150633:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150633:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150633:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150634:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
[1:1:0927/150634:ERROR:WebRemoteFrameImpl.cpp(213)] NOTREACHED() hit.
...

As many as 100 such messages / second.



Please provide any additional information below. Attach a screenshot if
possible.

From Feedback Report:
https://feedback.corp.google.com/product/208/neutron?lView=rd&lReport=12399895675

UserAgentString: Mozilla/5.0 (X11; CrOS aarch64 8743.25.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.24 Safari/537.36

From https://chromium.googlesource.com/chromium/src/+/master/third_party/WebKit/Source/web/WebRemoteFrameImpl.cpp

This seems to be:

void WebRemoteFrameImpl::addMessageToConsole(const WebConsoleMessage&)
{
    NOTREACHED();
}

Assigning to dcheng@ to help triage, since he was unfortunate to have originally added this function :-).