[heap] Integrate embedder heap tracer into incremental marking

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 ae7b4676aed293638cec1259a51c29a5f11113d5..59aca48c6956e47a258b613c6ce30f1df5b2f891 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2206,6 +2206,11 @@ void MarkCompactCollector::SetEmbedderHeapTracer(EmbedderHeapTracer* tracer) {
   embedder_heap_tracer_ = tracer;
 }
 
+bool MarkCompactCollector::RequiresImmediateWrapperProcessing() {
+  const size_t kTooManyWrappers = 500;
+  return wrappers_to_trace_.size() > kTooManyWrappers;
+}
+
 void MarkCompactCollector::RegisterWrappersWithEmbedderHeapTracer() {
   DCHECK(UsingEmbedderHeapTracer());
   if (wrappers_to_trace_.empty()) {