[heap] Take page lock when scavenging old to new references in Scavenger.

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 6651ad01698806dd70e99c411115e520df51bae0..e309096f0fabfd805179a24a48d3b073169ab020 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2369,11 +2369,12 @@ void MinorMarkCompactCollector::MarkLiveObjects() {
   {
     TRACE_GC(heap()->tracer(),
              GCTracer::Scope::MINOR_MC_MARK_OLD_TO_NEW_POINTERS);
-    RememberedSet<OLD_TO_NEW>::Iterate(heap(), [this](Address addr) {
-      return CheckAndMarkObject(heap(), addr);
-    });
+    RememberedSet<OLD_TO_NEW>::Iterate(
+        heap(), NON_SYNCHRONIZED,
+        [this](Address addr) { return CheckAndMarkObject(heap(), addr); });
     RememberedSet<OLD_TO_NEW>::IterateTyped(
-        heap(), [this](SlotType type, Address host_addr, Address addr) {
+        heap(), NON_SYNCHRONIZED,
+        [this](SlotType type, Address host_addr, Address addr) {
           return UpdateTypedSlotHelper::UpdateTypedSlot(
               isolate(), type, addr, [this](Object** addr) {
                 return CheckAndMarkObject(heap(),