gin test - add simple file access for JS

gin/test/run_js_tests.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "gin/test/file_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace gin {
 namespace {
 
 base::FilePath BasePath() {
   base::FilePath path;
   PathService::Get(base::DIR_SOURCE_ROOT, &path);
   return path.AppendASCII("gin");
 }
 
 void RunTest(const base::FilePath& path) {
   FileRunnerDelegate delegate;
   RunTestFromFile(path, &delegate);
 }
 
+TEST(JSTest, File) {
+  RunTest(BasePath()
+          .AppendASCII("test")
+          .AppendASCII("file_unittests.js"));
+}
+
 TEST(JSTest, GTest) {
   RunTest(BasePath()
           .AppendASCII("test")
           .AppendASCII("gtest_unittests.js"));
 }
 
 TEST(JSTest, ModuleRegistry) {
   RunTest(BasePath()
           .AppendASCII("modules")
           .AppendASCII("module_registry_unittests.js"));
 }
 
 }  // namespace
 }  // gin