Revert of [heap] Do not invoke GC to make heap iterable.

test/cctest/heap/test-heap.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 5556 matching lines @@
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   Heap* heap = isolate->heap();
   HandleScope handle_scope(isolate);
 
   Handle<FixedArray> o1 = isolate->factory()->NewFixedArray(kFixedArrayLen);
   Handle<FixedArray> o2 = isolate->factory()->NewFixedArray(kFixedArrayLen);
   CHECK(heap->InNewSpace(*o1));
   CHECK(heap->InNewSpace(*o2));
 
-  HeapIterator it(heap, i::HeapObjectsFiltering::kFilterUnreachable);
+  HeapIterator it(heap, i::HeapIterator::kFilterUnreachable);
 
   // Replace parts of an object placed before a live object with a filler. This
   // way the filler object shares the mark bits with the following live object.
   o1->Shrink(kFixedArrayLen - 1);
 
   for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
     // Let's not optimize the loop away.
     CHECK(obj->address() != nullptr);
   }
 }
@@ skipping 1162 matching lines @@
 
   intptr_t size_before = heap->SizeOfObjects();
   Handle<FixedArray> array = isolate->factory()->NewFixedArray(200000);
   array->Shrink(1);
   intptr_t size_after = heap->SizeOfObjects();
   CHECK_EQ(size_after, size_before + array->Size());
 }
 
 }  // namespace internal
 }  // namespace v8