I'm filing this to track the followup work mentioned in https://chromium-review.googlesource.com/c/chromium/src/+/852982#message-b9b9df3b20a5c9369a76561c47425fc6ea5fe5ef, which was fixing  issue 799399 .  In particular, we need to:

- Update comments on FastShutdownIfPossible to also mention pending views.

- Look at whether chrome::CloseWebContentses is correct when it counts the numbers of tabs in the presence of OOPIFs and/or process reuse.

- Fix MockRenderProcessHost to also properly use pending views.

- See if RFHI::AllowBindings also has a bug with pending views.  Currently it checks "GetProcess()->GetActiveViewCount() > 1".