[api] Support sharing prototypes between FunctionTemplates

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 48d0c156e7fb76b3e03ffda22c0bb7ac27c3f52d..aa8396a2be182c5f78a7b8cc41ffa51218ecb3c8 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -26159,3 +26159,29 @@ TEST(InternalFieldsOnDataView) {
              array->GetAlignedPointerFromInternalField(i));
   }
 }
+
+TEST(SetPrototypeTemplate) {
+  LocalContext env;
+  v8::Isolate* isolate = env->GetIsolate();
+  v8::HandleScope scope(isolate);
+
+  Local<FunctionTemplate> HTMLElementTemplate = FunctionTemplate::New(isolate);
+  Local<FunctionTemplate> HTMLImageElementTemplate =
+      FunctionTemplate::New(isolate);
+  HTMLImageElementTemplate->Inherit(HTMLElementTemplate);
+
+  Local<FunctionTemplate> ImageTemplate = FunctionTemplate::New(isolate);
+  ImageTemplate->SetPrototypeProviderTemplate(HTMLImageElementTemplate);
+
+  Local<Function> HTMLImageElement =
+      HTMLImageElementTemplate->GetFunction(env.local()).ToLocalChecked();
+  Local<Function> Image =
+      ImageTemplate->GetFunction(env.local()).ToLocalChecked();
+
+  CHECK(env->Global()
+            ->Set(env.local(), v8_str("HTMLImageElement"), HTMLImageElement)
+            .FromJust());
+  CHECK(env->Global()->Set(env.local(), v8_str("Image"), Image).FromJust());
+
+  ExpectTrue("Image.prototype === HTMLImageElement.prototype");
+}