Revert "Revert "put back the unused virtuals in Vector<>""

This reverts commit 225c66a48cdc3acef21ee380dc134449749d3cb3

Change-Id: If31a04b81052cbc7dd7bf237c07107c33066d03d
libutils: refbase: jellybean mr1 compat

Change-Id: Ideee0c3814a17b47f70fd612d27067fe19ae698d