Expose requireAsync method and make it more robust

extensions/renderer/api/mojo_private/mojo_private_unittest.cc

Index: extensions/renderer/api/mojo_private/mojo_private_unittest.cc
diff --git a/extensions/renderer/api/mojo_private/mojo_private_unittest.cc b/extensions/renderer/api/mojo_private/mojo_private_unittest.cc
index d9607bf674b0198697db739605d36a5992fdc581..af1801ecdd862e81cce0097a0d85737fd806800c 100644
--- a/extensions/renderer/api/mojo_private/mojo_private_unittest.cc
+++ b/extensions/renderer/api/mojo_private/mojo_private_unittest.cc
@@ -45,4 +45,14 @@ TEST_F(MojoPrivateApiTest, DefineModuleDoesNotExist) {
                     "does not exist!"));
 }
 
+TEST_F(MojoPrivateApiTest, RequireAsync) {
+  ASSERT_NO_FATAL_FAILURE(
+      RunTest("mojo_private_unittest.js", "testRequireAsync"));
+}
+
+TEST_F(MojoPrivateApiTest, DefineAndRequire) {
+  ASSERT_NO_FATAL_FAILURE(
+      RunTest("mojo_private_unittest.js", "testDefineAndRequire"));
+}
+
 }  // namespace extensions