Do not mark prototype transitions as weak container in heap snapshot.

src/profiler/heap-snapshot-generator.cc

 // Copyright 2013 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.
 
 #include "src/profiler/heap-snapshot-generator.h"
 
 #include "src/code-stubs.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/objects-body-descriptors.h"
@@ skipping 1249 matching lines @@
   }
 }
 
 
 void V8HeapExplorer::ExtractMapReferences(int entry, Map* map) {
   Object* raw_transitions_or_prototype_info = map->raw_transitions();
   if (TransitionArray::IsFullTransitionArray(
           raw_transitions_or_prototype_info)) {
     TransitionArray* transitions =
         TransitionArray::cast(raw_transitions_or_prototype_info);
-    int transitions_entry = GetEntry(transitions)->index();
-
-    if (map->CanTransition()) {
-      if (transitions->HasPrototypeTransitions()) {
-        FixedArray* prototype_transitions =
-            transitions->GetPrototypeTransitions();
-        MarkAsWeakContainer(prototype_transitions);
-        TagObject(prototype_transitions, "(prototype transitions");
-        SetInternalReference(transitions, transitions_entry,
-                             "prototype_transitions", prototype_transitions);
-      }
-      // TODO(alph): transitions keys are strong links.
-      MarkAsWeakContainer(transitions);
+    if (map->CanTransition() && transitions->HasPrototypeTransitions()) {
+      TagObject(transitions->GetPrototypeTransitions(),
+                "(prototype transitions)");
     }
 
     TagObject(transitions, "(transition array)");
     SetInternalReference(map, entry, "transitions", transitions,
                          Map::kTransitionsOrPrototypeInfoOffset);
   } else if (TransitionArray::IsSimpleTransition(
                  raw_transitions_or_prototype_info)) {
     TagObject(raw_transitions_or_prototype_info, "(transition)");
     SetInternalReference(map, entry, "transition",
                          raw_transitions_or_prototype_info,
@@ skipping 1834 matching lines @@
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8