The deferred handes list belongs to the Isolate and not to the

src/isolate.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1037 matching lines @@
     return date_cache_;
   }
 
   void set_date_cache(DateCache* date_cache) {
     if (date_cache != date_cache_) {
       delete date_cache_;
     }
     date_cache_ = date_cache;
   }
 
+  void IterateDeferredHandles(ObjectVisitor* visitor);
+  void LinkDeferredHandles(DeferredHandles* deferred_handles);
+  void UnlinkDeferredHandles(DeferredHandles* deferred_handles);
+
  private:
   Isolate();
 
   friend struct GlobalState;
   friend struct InitializeGlobalState;
 
   enum State {
     UNINITIALIZED,    // Some components may not have been allocated.
     INITIALIZED       // All components are fully initialized.
   };
@@ skipping 203 matching lines @@
   // This class is huge and has a number of fields controlled by
   // preprocessor defines. Make sure the offsets of these fields agree
   // between compilation units.
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                              \
   static const intptr_t name##_debug_offset_;
   ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
   ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
+  DeferredHandles* deferred_handles_head_;
+
   friend class ExecutionAccess;
   friend class IsolateInitializer;
   friend class ThreadManager;
   friend class Simulator;
   friend class StackGuard;
   friend class ThreadId;
   friend class TestMemoryAllocatorScope;
   friend class v8::Isolate;
   friend class v8::Locker;
   friend class v8::Unlocker;
@@ skipping 137 matching lines @@
 
 // Mark the global context with out of memory.
 inline void Context::mark_out_of_memory() {
   global_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_