Remove reinvented wheel for partial snapshot cache.

src/serialize.cc

Index: src/serialize.cc
diff --git a/src/serialize.cc b/src/serialize.cc
index 1d18fac04c086342035649eb3349f55c4e724ca6..f30c8e046a699179ae0c3d8806ae7b1e1becc5b9 100644
--- a/src/serialize.cc
+++ b/src/serialize.cc
@@ -998,7 +998,7 @@ void Deserializer::ReadData(Object** current, Object** limit, int source_space,
         emit_write_barrier = isolate->heap()->InNewSpace(new_object);          \
       } else if (where == kPartialSnapshotCache) {                             \
         int cache_index = source_.GetInt();                                    \
-        new_object = isolate->serialize_partial_snapshot_cache()[cache_index]; \
+        new_object = isolate->partial_snapshot_cache()->at(cache_index);       \
         emit_write_barrier = isolate->heap()->InNewSpace(new_object);          \
       } else if (where == kExternalReference) {                                \
         int skip = source_.GetInt();                                           \
@@ -1508,43 +1508,34 @@ void Serializer::EncodeReservations(
 void SerializerDeserializer::Iterate(Isolate* isolate,
                                      ObjectVisitor* visitor) {
   if (isolate->serializer_enabled()) return;
-  for (int i = 0; ; i++) {
-    if (isolate->serialize_partial_snapshot_cache_length() <= i) {
-      // Extend the array ready to get a value from the visitor when
-      // deserializing.
-      isolate->PushToPartialSnapshotCache(Smi::FromInt(0));
-    }
-    Object** cache = isolate->serialize_partial_snapshot_cache();
-    visitor->VisitPointers(&cache[i], &cache[i + 1]);
+  List<Object*>* cache = isolate->partial_snapshot_cache();
+  for (int i = 0;; ++i) {
+    // Extend the array ready to get a value when deserializing.
+    if (cache->length() <= i) cache->Add(Smi::FromInt(0));
+    visitor->VisitPointer(&cache->at(i));
     // Sentinel is the undefined object, which is a root so it will not normally
     // be found in the cache.
-    if (cache[i] == isolate->heap()->undefined_value()) {
-      break;
-    }
+    if (cache->at(i)->IsUndefined()) break;
   }
 }
 
 
 int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) {
   Isolate* isolate = this->isolate();
-
-  for (int i = 0;
-       i < isolate->serialize_partial_snapshot_cache_length();
-       i++) {
-    Object* entry = isolate->serialize_partial_snapshot_cache()[i];
+  List<Object*>* cache = isolate->partial_snapshot_cache();
+  for (int i = 0; i < cache->length(); ++i) {
+    Object* entry = cache->at(i);
     if (entry == heap_object) return i;
   }
 
   // We didn't find the object in the cache.  So we add it to the cache and
   // then visit the pointer so that it becomes part of the startup snapshot
   // and we can refer to it from the partial snapshot.
-  int length = isolate->serialize_partial_snapshot_cache_length();
-  isolate->PushToPartialSnapshotCache(heap_object);
+  cache->Add(heap_object);
   startup_serializer_->VisitPointer(reinterpret_cast<Object**>(&heap_object));
   // We don't recurse from the startup snapshot generator into the partial
   // snapshot generator.
-  DCHECK(length == isolate->serialize_partial_snapshot_cache_length() - 1);
-  return length;
+  return cache->length() - 1;
 }