8151171: Bring g1ConcurrentMark files up to current coding conventions
Summary: Improve method naming, bracketing, use of _g1h member and general cleanup.
Reviewed-by: sangheki, sjohanss
^build/
^dist/
^.idea/
nbproject/private/
^webrev
^.src-rev$
^.jib/
\.DS_Store
\.metadata/
\.recommenders/
test/nashorn/script/external
test/nashorn/lib
NashornProfile.txt
.*/JTreport/.*
.*/JTwork/.*