[serializer] include global proxy in additional context snapshots.

src/snapshot/startup-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/startup-serializer.h"
 
 #include "src/objects-inl.h"
 #include "src/v8threads.h"
 
 namespace v8 {
@@ skipping 98 matching lines @@
   serializing_builtins_ = (tag == VisitorSynchronization::kHandleScope);
   sink_.Put(kSynchronize, "Synchronize");
 }
 
 void StartupSerializer::SerializeStrongReferences() {
   Isolate* isolate = this->isolate();
   // No active threads.
   CHECK_NULL(isolate->thread_manager()->FirstThreadStateInUse());
   // No active or weak handles.
   CHECK(isolate->handle_scope_implementer()->blocks()->is_empty());
-  CHECK_EQ(0, isolate->global_handles()->NumberOfWeakHandles());
+  CHECK_EQ(0, isolate->global_handles()->global_handles_count());
   CHECK_EQ(0, isolate->eternal_handles()->NumberOfHandles());
-  // We don't support serializing installed extensions.
-  CHECK(!isolate->has_installed_extensions());
   // First visit immortal immovables to make sure they end up in the first page.
   serializing_immortal_immovables_roots_ = true;
   isolate->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG_ROOT_LIST);
   // Check that immortal immovable roots are allocated on the first page.
   CHECK(HasNotExceededFirstPageOfEachSpace());
   serializing_immortal_immovables_roots_ = false;
   // Visit the rest of the strong roots.
   // Clear the stack limits to make the snapshot reproducible.
   // Reset it again afterwards.
   isolate->heap()->ClearStackLimits();
@@ skipping 39 matching lines @@
   if (root_index == Heap::kStackLimitRootIndex ||
       root_index == Heap::kRealStackLimitRootIndex) {
     return true;
   }
   return Heap::RootIsImmortalImmovable(root_index) !=
          serializing_immortal_immovables_roots_;
 }
 
 }  // namespace internal
 }  // namespace v8