[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..436dfdef9ca3e27948e5ef0126af1f19f95cf684 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -26159,3 +26159,25 @@ 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();
+  Local<Function> Image = ImageTemplate->GetFunction();
+
+  env->Global()->Set(v8_str("HTMLImageElement"), HTMLImageElement);
+  env->Global()->Set(v8_str("Image"), Image);
+
+  ExpectTrue("Image.prototype === HTMLImageElement.prototype");
+}