Fix performance regression of heap snapshot generator that was

src/profiler/heap-snapshot-generator.h

 // Copyright 2013 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_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_
 #define V8_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_
 
 #include "include/v8-profiler.h"
 #include "src/base/platform/time.h"
 #include "src/objects.h"
@@ skipping 378 matching lines @@
   void ExtractAllocationSiteReferences(int entry, AllocationSite* site);
   void ExtractJSArrayBufferReferences(int entry, JSArrayBuffer* buffer);
   void ExtractFixedArrayReferences(int entry, FixedArray* array);
   void ExtractPropertyReferences(JSObject* js_obj, int entry);
   void ExtractAccessorPairProperty(JSObject* js_obj, int entry, Name* key,
                                    Object* callback_obj, int field_offset = -1);
   void ExtractElementReferences(JSObject* js_obj, int entry);
   void ExtractInternalReferences(JSObject* js_obj, int entry);
 
   bool IsEssentialObject(Object* object);
+  bool IsEssentialHiddenReference(Object* parent, int field_offset);
+
   void SetContextReference(HeapObject* parent_obj,
                            int parent,
                            String* reference_name,
                            Object* child,
                            int field_offset);
   void SetNativeBindReference(HeapObject* parent_obj,
                               int parent,
                               const char* reference_name,
                               Object* child);
   void SetElementReference(HeapObject* parent_obj,
                            int parent,
                            int index,
                            Object* child);
   void SetInternalReference(HeapObject* parent_obj,
                             int parent,
                             const char* reference_name,
                             Object* child,
                             int field_offset = -1);
   void SetInternalReference(HeapObject* parent_obj,
                             int parent,
                             int index,
                             Object* child,
                             int field_offset = -1);
-  void SetHiddenReference(HeapObject* parent_obj,
-                          int parent,
-                          int index,
-                          Object* child);
+  void SetHiddenReference(HeapObject* parent_obj, int parent, int index,
+                          Object* child, int field_offset);
   void SetWeakReference(HeapObject* parent_obj,
                         int parent,
                         const char* reference_name,
                         Object* child_obj,
                         int field_offset);
   void SetWeakReference(HeapObject* parent_obj,
                         int parent,
                         int index,
                         Object* child_obj,
                         int field_offset);
@@ skipping 182 matching lines @@
   friend class HeapSnapshotJSONSerializerIterator;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshotJSONSerializer);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PROFILER_HEAP_SNAPSHOT_GENERATOR_H_