[deserializer] Make large object deserialization GC safe

src/heap/incremental-marking.cc

Index: src/heap/incremental-marking.cc
diff --git a/src/heap/incremental-marking.cc b/src/heap/incremental-marking.cc
index e5c65705c9726b7245eb3361af4566df77e68c20..77eee708c75bdba116404394494c6990899e88d2 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -1102,8 +1102,10 @@ size_t IncrementalMarking::StepSizeToMakeProgress() {
 }
 
 void IncrementalMarking::AdvanceIncrementalMarkingOnAllocation() {
+  // Code using an AlwaysAllocateScope assumes that the GC state does not
+  // change; that implies that no marking steps must be performed.
   if (heap_->gc_state() != Heap::NOT_IN_GC || !FLAG_incremental_marking ||
-      (state_ != SWEEPING && state_ != MARKING)) {
+      (state_ != SWEEPING && state_ != MARKING) || heap_->always_allocate()) {
     return;
   }