Hide implementation detail inside a function (#10652)
Hide implementation detail inside a function (#10652)

* Hide implementation detail inside a function

Not the best idea to reach to the mutex of the other type directly from
layering and incapsulation perspective.

Change-Id: I90cd66ab97ceb7a66d3c27db86fb0c6d0af33160

* one more place

Change-Id: I20ff042b1b1c40812e016a8d67dc00efe8b139b9
knative/serving,knative/serving