Track allocation info

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index da78b18a512764dae3510e6fcc6dfaa66665e129..ba3882c98c7dc0def37648c78335061a6294076a 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -259,6 +259,12 @@ class Isolate;
 class WeakObjectRetainer;
 
 
+enum AllocationOriginTrackMode {
+  DONT_TRACK_ALLOCATION_ORIGIN,
+  TRACK_ALLOCATION_ORIGIN
+};
+
+
 typedef String* (*ExternalStringTableUpdaterCallback)(Heap* heap,
                                                       Object** pointer);
 
@@ -564,8 +570,9 @@ class Heap {
   MUST_USE_RESULT MaybeObject* AllocateEmptyJSArray(
       ElementsKind elements_kind,
       PretenureFlag pretenure = NOT_TENURED) {
-    return AllocateJSArrayAndStorage(elements_kind, 0, 0,
-                                     DONT_INITIALIZE_ARRAY_ELEMENTS,
+    return AllocateJSArrayAndStorage(elements_kind, 0,
+                                     JSArray::kPreallocatedArrayElements,
+                                     INITIALIZE_ARRAY_ELEMENTS_WITH_HOLE,
                                      pretenure);
   }
 
@@ -593,7 +600,9 @@ class Heap {
   // Returns a deep copy of the JavaScript object.
   // Properties and elements are copied too.
   // Returns failure if allocation failed.
-  MUST_USE_RESULT MaybeObject* CopyJSObject(JSObject* source);
+  MUST_USE_RESULT MaybeObject* CopyJSObject(
+      JSObject* source,
+      AllocationOriginTrackMode mode = DONT_TRACK_ALLOCATION_ORIGIN);
 
   // Allocates the function prototype.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation