init: Document the locking strategy used in class PropWaiterState

Let the compiler verify that lock_ is held when any of the data members
are accessed.

Bug: 266255006
Change-Id: I71b341815d84ab530627d934ad4d4681b652b9d8
Signed-off-by: Bart Van Assche <bvanassche@google.com>
1 file changed