Put V8 extras into the snapshot

src/snapshot/serialize.cc

Index: src/snapshot/serialize.cc
diff --git a/src/snapshot/serialize.cc b/src/snapshot/serialize.cc
index 81e071c0fb05809d6b905fe8c5373bbb8e6bc5e6..5b4bf9b4da6a32a03b11df1d3924bb348f8cf0f1 100644
--- a/src/snapshot/serialize.cc
+++ b/src/snapshot/serialize.cc
@@ -577,6 +577,13 @@ void Deserializer::Deserialize(Isolate* isolate) {
     }
   }
 
+  for (int i = 0; i < ExtraNatives::GetBuiltinsCount(); i++) {
+    Object* source = isolate_->heap()->extra_natives_source_cache()->get(i);
+    if (!source->IsUndefined()) {
+      ExternalOneByteString::cast(source)->update_data_cache();
+    }
+  }
+
   for (int i = 0; i < CodeStubNatives::GetBuiltinsCount(); i++) {
     Object* source = isolate_->heap()->code_stub_natives_source_cache()->get(i);
     if (!source->IsUndefined()) {
@@ -1181,6 +1188,11 @@ bool Deserializer::ReadData(Object** current, Object** limit, int source_space,
                                       current);
         break;
 
+      case kExtraNativesStringResource:
+        current = CopyInNativesSource(
+            ExtraNatives::GetScriptSource(source_.Get()), current);
+        break;
+
       case kCodeStubNativesStringResource:
         current = CopyInNativesSource(
             CodeStubNatives::GetScriptSource(source_.Get()), current);
@@ -2192,6 +2204,12 @@ void Serializer::ObjectSerializer::VisitExternalOneByteString(
     return;
   }
   if (SerializeExternalNativeSourceString(
+          ExtraNatives::GetBuiltinsCount(), resource_pointer,
+          serializer_->isolate()->heap()->extra_natives_source_cache(),
+          kExtraNativesStringResource)) {
+    return;
+  }
+  if (SerializeExternalNativeSourceString(
           CodeStubNatives::GetBuiltinsCount(), resource_pointer,
           serializer_->isolate()->heap()->code_stub_natives_source_cache(),
           kCodeStubNativesStringResource)) {