Store the bits of a small type into the lower bits
of a pointer type that are free due to alignment.
Furthermore, reordering of members to reduce size of some classes.

Change-Id: I3c619cb74053f64995ea7d0cb395e8edda604f18
Reviewed-on: https://chromium-review.googlesource.com/c/1273019
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56726}