Use EmbedderHeapTracer instead of object grouping when trace_embedder_heap flag is set

src/heap/mark-compact.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include "src/base/bits.h"
 #include "src/heap/spaces.h"
 #include "src/heap/store-buffer.h"
@@ skipping 559 matching lines @@
       case CODE_SPACE:
         return &swept_code_space_pages_;
       case MAP_SPACE:
         return &swept_map_space_pages_;
       default:
         UNREACHABLE();
     }
     return nullptr;
   }
 
+  std::vector<std::pair<void*, void*>>& wrappers_to_trace() {
+    return wrappers_to_trace_;
+  }
+
+  void SetEmbedderHeapTracer(EmbedderHeapTracer* tracer);
+
+  EmbedderHeapTracer* embedder_heap_tracer() { return embedder_heap_tracer_; }
+
+  bool UsingEmbedderHeapTracer() { return embedder_heap_tracer(); }
+
+  void TracePossibleWrapper(JSObject* js_object);
+
+  void RegisterExternallyReferencedObject(Object** object);
+
  private:
   class EvacuateNewSpaceVisitor;
   class EvacuateOldSpaceVisitor;
   class EvacuateVisitorBase;
   class HeapObjectVisitor;
   class SweeperTask;
 
   typedef std::vector<Page*> SweepingList;
 
   explicit MarkCompactCollector(Heap* heap);
@@ skipping 81 matching lines @@
   void MarkStringTable(RootMarkingVisitor* visitor);
 
   // Mark objects reachable (transitively) from objects in the marking stack
   // or overflowed in the heap.
   void ProcessMarkingDeque();
 
   // Mark objects reachable (transitively) from objects in the marking stack
   // or overflowed in the heap.  This respects references only considered in
   // the final atomic marking pause including the following:
   //    - Processing of objects reachable through Harmony WeakMaps.
-  //    - Objects reachable due to host application logic like object groups
-  //      or implicit references' groups.
+  //    - Objects reachable due to host application logic like object groups,
+  //      implicit references' groups, or embedder heap tracing.
   void ProcessEphemeralMarking(ObjectVisitor* visitor,
                                bool only_process_harmony_weak_collections);
 
   // If the call-site of the top optimized code was not prepared for
   // deoptimization, then treat the maps in the code as strong pointers,
   // otherwise a map can die and deoptimize the code.
   void ProcessTopOptimizedFrame(ObjectVisitor* visitor);
 
   // Collects a list of dependent code from maps embedded in optimize code.
   DependentCode* DependentCodeListFromNonLiveMaps();
@@ skipping 113 matching lines @@
   static void VisitObject(HeapObject* obj);
 
   friend class UnmarkObjectVisitor;
   static void UnmarkObject(HeapObject* obj);
 #endif
 
   Heap* heap_;
   base::VirtualMemory* marking_deque_memory_;
   size_t marking_deque_memory_committed_;
   MarkingDeque marking_deque_;
+  std::vector<std::pair<void*, void*>> wrappers_to_trace_;
+
   CodeFlusher* code_flusher_;
+
+  EmbedderHeapTracer* embedder_heap_tracer_;
+
   bool have_code_to_deoptimize_;
 
   List<Page*> evacuation_candidates_;
   List<NewSpacePage*> newspace_evacuation_candidates_;
 
   base::Mutex swept_pages_mutex_;
   List<Page*> swept_old_space_pages_;
   List<Page*> swept_code_space_pages_;
   List<Page*> swept_map_space_pages_;
 
@@ skipping 33 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_MARK_COMPACT_H_