Net.ResourceDispatcherHost.RequestMode.Get, Net.ResourceDispatcherHost.RequestMode.Post, and Net.ResourceDispatcherHost.RequestMode.Post.WithPort are only recorded in ResourceDispatcherHost, which isn't used when the network service is enabled.  We should figure out if we can just remove the histograms, or if we still need them.  If the latter is the case, we'll need to figure out how to hook them up when the NetworkService is enabled.

I don't believe that hooking up this histogram should block experimenting with the network service on Windows Canary.

All these histograms are marked as expires_after="M69", so maybe we can just remove them?