Reland of "[heap] Report wrappers after processing the marking deque incrementally"

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 5421dd20700f64108905bbb84536b130b4011218..63a50f3c065214182cea28d92b3f7c22b88bf802 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1610,8 +1610,6 @@ void Heap::Scavenge() {
 
   scavenge_collector_->SelectScavengingVisitorsTable();
 
-  local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
-
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
   new_space_->Flip();
@@ -1719,6 +1717,10 @@ void Heap::Scavenge() {
   IncrementYoungSurvivorsCounter(PromotedSpaceSizeOfObjects() +
                                  new_space_->Size() - survived_watermark);
 
+  // Scavenger may find new wrappers by iterating objects promoted onto a black
+  // page.
+  local_embedder_heap_tracer()->RegisterWrappersWithRemoteTracer();
+
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
   SetGCState(NOT_IN_GC);