Remove the --collect-maps flag. Maps should be always collected.

src/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/v8.h"
 
 #include "src/heap-snapshot-generator-inl.h"
 
 #include "src/allocation-tracker.h"
 #include "src/code-stubs.h"
@@ skipping 1276 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 (FLAG_collect_maps && map->CanTransition()) {
+    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);
@@ skipping 1869 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