8169517: WhiteBox should provide concurrent GC phase control
Summary: Added WhiteBox API and G1 implementation.
Reviewed-by: shade, dfazunen

8154154: Separate G1 specific policy code from the CollectorPolicy class hierarchy
Summary: Move G1 runtime policy code to new class G1Policy which is unrelated to CollectorPolicy
Reviewed-by: kbarrett, ehelin

8151601: Cleanup locking of the Reference pending list
Reviewed-by: brutisso, stefank

8140257: Add support for "gc service threads" to ConcurrentGCThread
Summary: Push up the common run() and stop() methods from subclasses to ConcurrentGCThread, as well as declaration iof run_service() stop_service().
Reviewed-by: kbarrett, pliden

8148973: Rename g1/concurrentMark.{hpp,cpp,inline.hpp} to g1/g1ConcurrentMark.{hpp,cpp,inline.hpp}
Reviewed-by: tschatzl, mgerdin

8145092: Use Unified Logging for the GC logging
Summary: JEP-271. VM changes contributed by brutisso, test changes contributed by david.
Reviewed-by: sjohanss, david, brutisso
Contributed-by: bengt.rutisson@oracle.com, david.lindholm@oralce.com

8138920: Refactor the sampling thread from ConcurrentG1RefineThread
Summary: Helps enable running without concurrent refinement threads
Reviewed-by: brutisso, pliden

8129626: G1: set_in_progress() and clear_started() needs a barrier on non-TSO platforms
Summary: Also reviewed by vitalyd@gmail.com
Reviewed-by: pliden, bpittore, bdelsart

8129549: G1: Make sure the concurrent thread does not mix its logging with the STW pauses
Reviewed-by: pliden, tschatzl

8079792: GC directory structure cleanup
Reviewed-by: brutisso, stefank, david