Track cumulative objects and bytes copied for CC

Also print out these values when dumping GC performance info.

Bug: 12687968

Test: Test that values are reasonable after running EAAC.

Change-Id: Id04fadeaf52511560fd4b261f5287ea0a5dae9d4
diff --git a/runtime/gc/collector/concurrent_copying.h b/runtime/gc/collector/concurrent_copying.h
index 55c4570..5b0e2d6 100644
--- a/runtime/gc/collector/concurrent_copying.h
+++ b/runtime/gc/collector/concurrent_copying.h
@@ -272,6 +272,8 @@
   // How many objects and bytes we moved. Used for accounting.
   Atomic<size_t> bytes_moved_;
   Atomic<size_t> objects_moved_;
+  Atomic<uint64_t> cumulative_bytes_moved_;
+  Atomic<uint64_t> cumulative_objects_moved_;
 
   // The skipped blocks are memory blocks/chucks that were copies of
   // objects that were unused due to lost races (cas failures) at