Oilpan: Remove code duplication between PersistentBase and CrossThreadPersistent
Oilpan: Remove code duplication between PersistentBase and CrossThreadPersistent

This CL introduces PersistentConfiguration. Using the PersistentConfiguration as
a template parameter of PersistentBase, we can remove the code duplication
between PersistentBase and CrossThreadPersistent.

BUG=420515

Review URL: https://codereview.chromium.org/1264883002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@199802 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk