[inspector] always include user scripts in the snapshot.

src/snapshot/startup-serializer.cc

Index: src/snapshot/startup-serializer.cc
diff --git a/src/snapshot/startup-serializer.cc b/src/snapshot/startup-serializer.cc
index 4b27746f8eefa0cce128468249d2d25f526be12b..1d8cd23c839097067b59e9ca9abc4910e48b51bc 100644
--- a/src/snapshot/startup-serializer.cc
+++ b/src/snapshot/startup-serializer.cc
@@ -73,6 +73,9 @@ void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
     Address original_address = Foreign::cast(info->getter())->foreign_address();
     Foreign::cast(info->js_getter())->set_foreign_address(original_address);
     accessor_infos_.Add(info);
+  } else if (obj->IsScript() && Script::cast(obj)->IsUserJavaScript()) {
+    Script::cast(obj)->set_context_data(
+        isolate_->heap()->uninitialized_symbol());
   }
 
   // Object has not yet been serialized.  Serialize it here.