This DCHECK is difficult to reproduce.

Steps require enabling kBrowserContainerContainsNTP, although I have a feeling this would be reproducible with any page.

1) Start on NTP.
2) Open omnibox and type arlnow.com and go.
3) right before navigation finishes, tap back
4) If this doesn't work, repeat 2,3,4 until you DCHECK
-- This often takes me 5 or 6 minutes of regular back and forth. 

I can reproduce this in the simulator (iPhone X, iOS 12.1, although I don't think it's device/OS related)

It's very weird that during a didFinishNavigation webView.URL and context.url do not match...

There's also a `non-matching windowID` warning that may be unrelated.

Log:


[decidePolicyForNavigationResponse] https://www.arlnow.com/
[decidePolicyForNavigationResponse] https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: https://tpc.googlesyndication.com/safeframe/1-0-30/html/container.html webViewURL: https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: https://tpc.googlesyndication.com/safeframe/1-0-30/html/container.html webViewURL: https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: about:blank webViewURL: https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: about:blank webViewURL: https://www.arlnow.com/
[decidePolicyForNavigationResponse] https://www.arlnow.com/
[decidePolicyForNavigationResponse] https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: about:blank webViewURL: https://www.arlnow.com/
[decidePolicyForNavigationAction] requestURL: about:blank webViewURL: https://www.arlnow.com/
webViewURLDidChange: about://newtab/
[decidePolicyForNavigationAction] requestURL: about://newtab/ webViewURL: about://newtab/
[didFinishNavigation] <WKNavigation: 0x7fa860a8b700>: about://newtab/
[1108/204239.290203:FATAL:crw_web_controller.mm(5032)] Check failed: item->GetURL().EqualsIgnoringRef(currentWKItemURL). 
(lldb) expr item->GetURL()
  spec_ = "https://www.arlnow.com/"

(lldb) expr context->GetUrl()
  spec_ = "https://www.arlnow.com/"

(lldb) po webView.URL
about://newtab/

lldb:Continue

[didStartProvisionalNavigation] <WKNavigation: 0x7fa85cd2f9c0>: about://newtab/
webViewURLDidChange: https://www.arlnow.com/
[didFinishNavigation] <WKNavigation: 0x7fa85cd2f9c0>: https://www.arlnow.com/
[didCommitNavigation] <WKNavigation: 0x7fa85cd2f9c0>: https://www.arlnow.com/
webViewURLDidChange: about://newtab/
[didCommitNavigation] <WKNavigation: 0x7fa85cd2f9c0>: about://newtab/
[1108/204428.453043:WARNING:crw_web_controller.mm(2482)] Message from JS ignored due to non-matching windowID: A9D3B865AD410F0C0F7830CFEF33C786 != 54486BFA7DCF4124C9839A640D5F1252