Code review comment for lp:~vanvugt/mir/fix-1192618

> 144 + EXPECT_CALL(*buffer_allocation_strategy, create_swapper_new_buffers(_,_,_))
> 145 + .WillOnce(testing::Invoke(this, &ServerConfig::on_create_swapper));

> We can change this to use a stub, too, since this is not really a test expectation.

... at least according to the original test. But I guess we can consider it an expectation if we want.