Implicit references are missing in heap profiles

src/api.cc

 // 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 5465 matching lines @@
   i::Isolate* isolate = i::Isolate::UncheckedCurrent();
   if (isolate == NULL || !isolate->IsInitialized() ||
       IsDeadCheck(isolate, "v8::V8::AdjustAmountOfExternalAllocatedMemory()")) {
     return 0;
   }
   return isolate->heap()->AdjustAmountOfExternalAllocatedMemory(
       change_in_bytes);
 }
 
 
-void V8::SetGlobalGCPrologueCallback(GCCallback callback) {
-  i::Isolate* isolate = i::Isolate::Current();
-  if (IsDeadCheck(isolate, "v8::V8::SetGlobalGCPrologueCallback()")) return;
-  isolate->heap()->SetGlobalGCPrologueCallback(callback);
-}
-
-
-void V8::SetGlobalGCEpilogueCallback(GCCallback callback) {
-  i::Isolate* isolate = i::Isolate::Current();
-  if (IsDeadCheck(isolate, "v8::V8::SetGlobalGCEpilogueCallback()")) return;
-  isolate->heap()->SetGlobalGCEpilogueCallback(callback);
-}
-
-
 void V8::AddGCPrologueCallback(GCPrologueCallback callback, GCType gc_type) {
   i::Isolate* isolate = i::Isolate::Current();
   if (IsDeadCheck(isolate, "v8::V8::AddGCPrologueCallback()")) return;
   isolate->heap()->AddGCPrologueCallback(callback, gc_type);
 }
 
 
 void V8::RemoveGCPrologueCallback(GCPrologueCallback callback) {
   i::Isolate* isolate = i::Isolate::Current();
   if (IsDeadCheck(isolate, "v8::V8::RemoveGCPrologueCallback()")) return;
@@ skipping 1229 matching lines @@
 
   v->VisitPointers(blocks_.first(), first_block_limit_);
 
   for (int i = 1; i < blocks_.length(); i++) {
     v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
   }
 }
 
 
 } }  // namespace v8::internal