Introduce extras export object.

test/cctest/test-api.cc

 // Copyright 2012 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 21083 matching lines @@
     CHECK(!try_catch.HasCaught());
   }
 
   {
     v8::TryCatch try_catch;
     v8::Handle<Value> args[] = {v8_num(42), v8_num(555)};
     fun->Call(v8::Undefined(isolate), arraysize(args), args);
     CHECK(!try_catch.HasCaught());
   }
 }
+
+
+TEST(ExtrasExportsObject) {
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope handle_scope(isolate);
+  LocalContext env;
+
+  // standalone.gypi ensures we include the test-extra.js file, which should
+  // add the testExtraShouldReturnFive export
+  v8::Local<v8::Object> exports = env->GetExtrasExportsObject();
+
+  auto func =
+      exports->Get(v8_str("testExtraShouldReturnFive")).As<v8::Function>();
+  auto undefined = v8::Undefined(isolate);
+  auto result = func->Call(undefined, 0, {}).As<v8::Number>();
+
+  CHECK(result->Value() == 5.0);
+}