ImmediateInterpreter: Suppress thumb movement even after finger leaves.
Previously, when fingers changed (e.g., when we transitioned from
finger + resting thumb -> just resting thumb), we would reevaluate
which finger is pointing, and decided that if there's just one finger,
it must point. This CL adds the ability to track thumbs across fingers
changing, so that in this case we continue to suppress motion from the
thumb. If the thumb leaves the pad and comes back, we will reevaluate
at that point and allow it to point, if it's the only contact.
BUG=chromium-os:21933
TEST=unittest, tested on device
Change-Id: I10f9ab935778a733ed5fdf134808c152dc7cee78
4 files changed
