[heap] Remove unused support for heap iterator size function.

src/globals.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_GLOBALS_H_
 #define V8_GLOBALS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 554 matching lines @@
 struct CodeDesc {
   byte* buffer;
   int buffer_size;
   int instr_size;
   int reloc_size;
   int constant_pool_size;
   Assembler* origin;
 };
 
 
-// Callback function used for iterating objects in heap spaces,
-// for example, scanning heap objects.
-typedef int (*HeapObjectCallback)(HeapObject* obj);
-
-
 // Callback function used for checking constraints when copying/relocating
 // objects. Returns true if an object can be copied/relocated from its
 // old_addr to a new_addr.
 typedef bool (*ConstraintCallback)(Address new_addr, Address old_addr);
 
 
 // Callback function on inline caches, used for iterating over inline caches
 // in compiled code.
 typedef void (*InlineCacheCallback)(Code* code, Address ic);
 
@@ skipping 445 matching lines @@
 inline FunctionKind WithObjectLiteralBit(FunctionKind kind) {
   kind = static_cast<FunctionKind>(kind | FunctionKind::kInObjectLiteral);
   DCHECK(IsValidFunctionKind(kind));
   return kind;
 }
 } }  // namespace v8::internal
 
 namespace i = v8::internal;
 
 #endif  // V8_GLOBALS_H_