Add kAbortIncrementalMarkingMask flag for GC.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 7c59c0471e4b81c74169ad75beff6a50776168e1..3db91ced8b44eed2654394303502700c1e50024f 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -686,8 +686,10 @@ void MarkCompactCollector::Prepare(GCTracer* tracer) {
   }
 #endif
 
-  // Clear marking bits for precise sweeping to collect all garbage.
-  if (was_marked_incrementally_ && PreciseSweepingRequired()) {
+  // Clear marking bits if incremental marking is aborted (required for
+  // precise sweeping to collect all garbage).
+  ASSERT(abort_incremental_marking_ || !sweep_precisely_);
+  if (was_marked_incrementally_ && abort_incremental_marking_) {
     heap()->incremental_marking()->Abort();
     ClearMarkbits();
     AbortCompaction();