[serializer] prepare attached references for general use.

src/snapshot/partial-serializer.cc

 // Copyright 2016 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/snapshot/partial-serializer.h"
 
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 PartialSerializer::PartialSerializer(Isolate* isolate,
                                      Serializer* startup_snapshot_serializer,
                                      SnapshotByteSink* sink)
     : Serializer(isolate, sink),
       startup_serializer_(startup_snapshot_serializer),
-      global_object_(NULL),
       next_partial_cache_index_(0) {
   InitializeCodeAddressMap();
 }
 
 PartialSerializer::~PartialSerializer() {
   OutputStatistics("PartialSerializer");
 }
 
 void PartialSerializer::Serialize(Object** o) {
   if ((*o)->IsContext()) {
     Context* context = Context::cast(*o);
-    global_object_ = context->global_object();
-    back_reference_map()->AddGlobalProxy(context->global_proxy());
+    reference_map()->AddAttachedReference(context->global_proxy());
     // The bootstrap snapshot has a code-stub context. When serializing the
     // partial snapshot, it is chained into the weak context list on the isolate
     // and it's next context pointer may point to the code-stub context.  Clear
     // it before serializing, it will get re-added to the context list
     // explicitly when it's loaded.
     if (context->IsNativeContext()) {
       context->set(Context::NEXT_CONTEXT_LINK,
                    isolate_->heap()->undefined_value());
       DCHECK(!context->global_object()->IsUndefined());
     }
@@ skipping 26 matching lines @@
     int cache_index = PartialSnapshotCacheIndex(obj);
     sink_->Put(kPartialSnapshotCache + how_to_code + where_to_point,
                "PartialSnapshotCache");
     sink_->PutInt(cache_index, "partial_snapshot_cache_index");
     return;
   }
 
   // Pointers from the partial snapshot to the objects in the startup snapshot
   // should go through the root array or through the partial snapshot cache.
   // If this is not the case you may have to add something to the root array.
-  DCHECK(!startup_serializer_->back_reference_map()->Lookup(obj).is_valid());
+  DCHECK(!startup_serializer_->reference_map()->Lookup(obj).is_valid());
   // All the internalized strings that the partial snapshot needs should be
   // either in the root table or in the partial snapshot cache.
   DCHECK(!obj->IsInternalizedString());
 
   if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
 
   FlushSkip(skip);
 
   // Clear literal boilerplates.
   if (obj->IsJSFunction()) {
@@ skipping 26 matching lines @@
   // would cause dupes.
   DCHECK(!o->IsScript());
   return o->IsName() || o->IsSharedFunctionInfo() || o->IsHeapNumber() ||
          o->IsCode() || o->IsScopeInfo() || o->IsAccessorInfo() ||
          o->map() ==
              startup_serializer_->isolate()->heap()->fixed_cow_array_map();
 }
 
 }  // namespace internal
 }  // namespace v8