base: Do not allow MessagePumpObservers to consume events.
There is currently a single message-pump observer that can consume an event,
and it does so only when the num-lock key is pressed on Chrome OS. But it
doesn't need to consume the event, because no other dispatcher/observer cares
about this event. So remove a MessagePumpObserver's ability to consume an
event. This makes the code cleaner, and easier to understand.
BUG=354062
R=darin@chromium.org, derat@chromium.org, sky@chromium.org
Review URL: https://codereview.chromium.org/
223483002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262019 0039d316-1c4b-4281-b951-d872f2087c98