Check if there is still time before finalizing an incremental collection.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 69fc579e2fe65ec359644efd01362e5bea362d61..da3ef1e0991fffe02431fb776ece61057811ac4f 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -965,6 +965,8 @@ void MarkCompactCollector::Finish() {
     Deoptimizer::DeoptimizeMarkedCode(isolate());
     have_code_to_deoptimize_ = false;
   }
+
+  heap_->incremental_marking()->ClearIdleMarkingDelayCounter();
 }
 
 
@@ -2040,6 +2042,11 @@ void MarkCompactCollector::MarkAllocationSite(AllocationSite* site) {
 }
 
 
+bool MarkCompactCollector::IsMarkingDequeEmpty() {
+  return marking_deque_.IsEmpty();
+}
+
+
 void MarkCompactCollector::MarkRoots(RootMarkingVisitor* visitor) {
   // Mark the heap roots including global variables, stack variables,
   // etc., and all objects reachable from them.