Estimate a (close) upper bound on the size of black-marked objects on each page.

src/builtins.cc

 // Copyright 2011 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 345 matching lines @@
   // Technically in new space this write might be omitted (except for
   // debug mode which iterates through the heap), but to play safer
   // we still do it.
   heap->CreateFillerObjectAt(elms->address(), to_trim * kPointerSize);
 
   former_start[to_trim] = heap->fixed_array_map();
   former_start[to_trim + 1] = Smi::FromInt(len - to_trim);
 
   // Maintain marking consistency for HeapObjectIterator and
   // IncrementalMarking.
-  heap->marking()->TransferMark(elms->address(),
-                                elms->address() + to_trim * kPointerSize);
+  int size_delta = to_trim * kPointerSize;
+  if (heap->marking()->TransferMark(elms->address(),
+                                    elms->address() + size_delta)) {
+    MemoryChunk::IncrementLiveBytes(elms->address(), -size_delta);
+  }
 
   return FixedArray::cast(HeapObject::FromAddress(
       elms->address() + to_trim * kPointerSize));
 }
 
 
 static bool ArrayPrototypeHasNoElements(Heap* heap,
                                         Context* global_context,
                                         JSObject* array_proto) {
   // This method depends on non writability of Object and Array prototype
@@ skipping 1328 matching lines @@
   return Handle<Code>(code_address);                        \
 }
 BUILTIN_LIST_C(DEFINE_BUILTIN_ACCESSOR_C)
 BUILTIN_LIST_A(DEFINE_BUILTIN_ACCESSOR_A)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 
 
 } }  // namespace v8::internal