[serializer] include global proxy in additional context snapshots.

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/snapshot/startup-serializer.h"
 
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 PartialSerializer::PartialSerializer(
     Isolate* isolate, StartupSerializer* startup_serializer,
     v8::SerializeInternalFieldsCallback callback)
     : Serializer(isolate),
       startup_serializer_(startup_serializer),
       serialize_internal_fields_(callback) {
   InitializeCodeAddressMap();
 }
 
 PartialSerializer::~PartialSerializer() {
   OutputStatistics("PartialSerializer");
 }
 
-void PartialSerializer::Serialize(Object** o) {
+void PartialSerializer::Serialize(Object** o, bool include_global_proxy) {
   if ((*o)->IsContext()) {
     Context* context = Context::cast(*o);
-    reference_map()->AddAttachedReference(context->global_proxy());
+    if (!include_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(context->GetIsolate()));
       // Reset math random cache to get fresh random numbers.
@@ skipping 107 matching lines @@
       sink_.PutRaw(reinterpret_cast<const byte*>(data.data), data.raw_size,
                    "internal fields data");
       delete[] data.data;
     }
   }
   sink_.Put(kSynchronize, "Finished with internal fields data");
 }
 
 }  // namespace internal
 }  // namespace v8