Oilpan: rename EAGERLY_SWEEP() as EAGERLY_FINALIZED().

Renamed to make its purpose clearer; classes are to be annotated as
eagerly finalized when they either need to promptly release ownership of
non-heap objects, or when their destructors have an unavoidable need to
access other heap objects. Both kinds are considered very rare, but more
accurate control of finalization timing is sometimes needed & vital.

Also introduce a transition time version of the macro,
EAGERLY_FINALIZED_WILL_BE_REMOVED() for the places where eager finalization
is needed non-Oilpan once lazy sweeping is enabled. That class annotation
will be removed once the class is always on the heap.

R=haraken
BUG=420515

Review URL: https://codereview.chromium.org/1150863003

git-svn-id: svn://svn.chromium.org/blink/trunk@195887 bbb929c8-8fbe-4397-9dbb-9b2b20218538
4 files changed