1. Add user tag to the pointers traversed in the object store

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 20316 matching lines @@
   }
   result.set_label(label);
   AddTagToIsolate(isolate, result);
   return result.raw();
 }
 
 
 RawUserTag* UserTag::DefaultTag() {
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != NULL);
-  ASSERT(isolate->object_store() != NULL);
-  if (isolate->object_store()->default_tag() != UserTag::null()) {
+  if (isolate->default_tag() != UserTag::null()) {
     // Already created.
-    return isolate->object_store()->default_tag();
+    return isolate->default_tag();
   }
   // Create default tag.
   const UserTag& result = UserTag::Handle(isolate,
                                           UserTag::New(Symbols::Default()));
   ASSERT(result.tag() == UserTags::kDefaultUserTag);
-  isolate->object_store()->set_default_tag(result);
+  isolate->set_default_tag(result);
   return result.raw();
 }
 
 
 RawUserTag* UserTag::FindTagInIsolate(Isolate* isolate, const String& label) {
   ASSERT(isolate->tag_table() != GrowableObjectArray::null());
   const GrowableObjectArray& tag_table = GrowableObjectArray::Handle(
       isolate, isolate->tag_table());
   UserTag& other = UserTag::Handle(isolate);
   String& tag_label = String::Handle(isolate);
@@ skipping 64 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart