We might decide to start incremental marking immediately after finishing one cycle.

src/incremental-marking.cc

Index: src/incremental-marking.cc
diff --git a/src/incremental-marking.cc b/src/incremental-marking.cc
index bd0f0837b0bd5860d91d38fb8c890622db86bb02..0f29f73f5e585027b88650456e4d1f09e9da1117 100644
--- a/src/incremental-marking.cc
+++ b/src/incremental-marking.cc
@@ -453,8 +453,7 @@ void IncrementalMarking::EnsureMarkingDequeIsCommitted() {
 }
 
 void IncrementalMarking::UncommitMarkingDeque() {
-  ASSERT(state_ == STOPPED);
-  if (marking_deque_memory_committed_) {
+  if (state_ == STOPPED && marking_deque_memory_committed_) {
     bool success = marking_deque_memory_->Uncommit(
         reinterpret_cast<Address>(marking_deque_memory_->address()),
         marking_deque_memory_->size());