Revert of [Tracing] Use TracingCategoryObserver in gc statistics

src/heap/heap-inl.h

Index: src/heap/heap-inl.h
diff --git a/src/heap/heap-inl.h b/src/heap/heap-inl.h
index 4932b4483b2226cbd4ad77a7e19308b8b2e9dbb6..fc487d0cb70444f0de247121382644841a132828 100644
--- a/src/heap/heap-inl.h
+++ b/src/heap/heap-inl.h
@@ -12,7 +12,6 @@
 #include "src/heap/heap.h"
 #include "src/heap/incremental-marking-inl.h"
 #include "src/heap/mark-compact.h"
-#include "src/heap/object-stats.h"
 #include "src/heap/remembered-set.h"
 #include "src/heap/spaces-inl.h"
 #include "src/heap/store-buffer.h"
@@ -810,16 +809,6 @@
   set_serialized_templates(templates);
 }
 
-void Heap::CreateObjectStats() {
-  if (V8_LIKELY(FLAG_gc_stats == 0)) return;
-  if (!live_object_stats_) {
-    live_object_stats_ = new ObjectStats(this);
-  }
-  if (!dead_object_stats_) {
-    dead_object_stats_ = new ObjectStats(this);
-  }
-}
-
 AlwaysAllocateScope::AlwaysAllocateScope(Isolate* isolate)
     : heap_(isolate->heap()) {
   heap_->always_allocate_scope_count_.Increment(1);