[serializer] API to re-use global proxy in v8::Context::FromSnapshot.

src/snapshot/snapshot-common.cc

Index: src/snapshot/snapshot-common.cc
diff --git a/src/snapshot/snapshot-common.cc b/src/snapshot/snapshot-common.cc
index a393e72f4f5b06adf4267a9c11b0238e46a1e028..959ac56fa98aa6a182062c76126f53e24c6bb193 100644
--- a/src/snapshot/snapshot-common.cc
+++ b/src/snapshot/snapshot-common.cc
@@ -62,11 +62,6 @@ MaybeHandle<Context> Snapshot::NewContextFromSnapshot(
   SnapshotData snapshot_data(context_data);
   Deserializer deserializer(&snapshot_data);
 
-  if (context_index > 0) {
-    // A non-default context uses the global proxy from the snapshot.
-    DCHECK(global_proxy.is_null());
-  }
-
   MaybeHandle<Object> maybe_context =
       deserializer.DeserializePartial(isolate, global_proxy);
   Handle<Object> result;