Need to understand how we ended up hit-testing a widget when its local main frame is not valid anymore [1]. Should the widget still be connected if its local main frame is not valid? 

Similarly, we are hitting this case in dispatching as well [2].

[1] https://cs.chromium.org/chromium/src/third_party/blink/renderer/core/exported/web_view_impl.cc?type=cs&q=web_view_impl&g=0&l=3121

[2] https://cs.chromium.org/chromium/src/third_party/blink/renderer/core/exported/web_view_impl.cc?type=cs&g=0&l=1972