[snapshot] support including templates in the snapshot.

test/cctest/test-serialize.cc

 // Copyright 2007-2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2013 matching lines @@
       v8::Local<v8::Context> context =
           v8::Context::New(isolate, no_extension, no_template, no_object, 0);
       v8::Context::Scope context_scope(context);
       ExpectInt32("f()", 1337);
     }
     isolate->Dispose();
   }
   delete[] blob.data;
 }
 
-TEST(SnapshotCreatorGlobalTemplate) {
+TEST(SnapshotCreatorTemplates) {
   DisableTurbofan();
   v8::StartupData blob;
   {
     v8::SnapshotCreator creator(original_external_references);
     v8::Isolate* isolate = creator.GetIsolate();
     {
       v8::HandleScope handle_scope(isolate);
       v8::ExtensionConfiguration* no_extension = nullptr;
       v8::Local<v8::ObjectTemplate> global_template =
           v8::ObjectTemplate::New(isolate);
-      global_template->Set(
-          v8_str("f"), v8::FunctionTemplate::New(isolate, SerializedCallback));
+      v8::Local<v8::FunctionTemplate> callback =
+          v8::FunctionTemplate::New(isolate, SerializedCallback);
+      global_template->Set(v8_str("f"), callback);
       v8::Local<v8::Context> context =
           v8::Context::New(isolate, no_extension, global_template);
       v8::Context::Scope context_scope(context);
       ExpectInt32("f()", 42);
       CHECK_EQ(0, creator.AddContext(context));
+      CHECK_EQ(0, creator.AddTemplate(callback));
+      CHECK_EQ(1, creator.AddTemplate(global_template));
     }
     blob =
         creator.CreateBlob(v8::SnapshotCreator::FunctionCodeHandling::kClear);
   }
 
   {
     v8::Isolate::CreateParams params;
     params.snapshot_blob = &blob;
     params.array_buffer_allocator = CcTest::array_buffer_allocator();
     params.external_references = original_external_references;
     v8::Isolate* isolate = v8::Isolate::New(params);
     {
       v8::Isolate::Scope isolate_scope(isolate);
       {
         // Create a new context without a new object template.
         v8::HandleScope handle_scope(isolate);
         v8::ExtensionConfiguration* no_extension = nullptr;
         v8::Local<v8::ObjectTemplate> no_template =
             v8::Local<v8::ObjectTemplate>();
         v8::Local<v8::Value> no_object = v8::Local<v8::Value>();
         v8::Local<v8::Context> context =
             v8::Context::New(isolate, no_extension, no_template, no_object, 0);
         v8::Context::Scope context_scope(context);
         ExpectInt32("f()", 42);
+
+        // Retrieve the snapshotted object template.
+        v8::Local<v8::ObjectTemplate> obj_template =
+            v8::ObjectTemplate::FromSnapshot(isolate, 1);
+        CHECK(!obj_template.IsEmpty());
+        v8::Local<v8::Object> object =
+            obj_template->NewInstance(context).ToLocalChecked();
+        CHECK(context->Global()->Set(context, v8_str("o"), object).FromJust());
+        ExpectInt32("o.f()", 42);
+        // Check that it instantiates to the same prototype.
+        ExpectTrue("o.f.prototype === f.prototype");
+
+        // Retrieve the snapshotted function template.
+        v8::Local<v8::FunctionTemplate> fun_template =
+            v8::FunctionTemplate::FromSnapshot(isolate, 0);
+        CHECK(!fun_template.IsEmpty());
+        v8::Local<v8::Function> fun =
+            fun_template->GetFunction(context).ToLocalChecked();
+        CHECK(context->Global()->Set(context, v8_str("g"), fun).FromJust());
+        ExpectInt32("g()", 42);
+        // Check that it instantiates to the same prototype.
+        ExpectTrue("g.prototype === f.prototype");
       }
 
       {
         // Create a context with a new object template. It is merged into the
         // deserialized global object.
         v8::HandleScope handle_scope(isolate);
         v8::ExtensionConfiguration* no_extension = nullptr;
         v8::Local<v8::ObjectTemplate> global_template =
             v8::ObjectTemplate::New(isolate);
         global_template->Set(
@@ skipping 11 matching lines @@
   }
   delete[] blob.data;
 }
 
 TEST(SerializationMemoryStats) {
   FLAG_profile_deserialization = true;
   FLAG_always_opt = false;
   v8::StartupData blob = v8::V8::CreateSnapshotDataBlob();
   delete[] blob.data;
 }