Revert of Move file_handlers API from //chrome to //extensions

chrome/browser/extensions/api/file_handlers/directory_util_unittest.cc

+// Copyright 2016 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 "chrome/browser/extensions/api/file_handlers/directory_util.h"
+
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/run_loop.h"
+#include "chrome/test/base/testing_profile.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "content/public/test/test_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace extensions {
+namespace app_file_handler_util {
+namespace {
+
+const char kRandomPath[] = "/random/path";
+
+void OnCollectForEntriesPath(
+    std::set<base::FilePath>* output,
+    std::unique_ptr<std::set<base::FilePath>> path_directory_set) {
+  *output = *path_directory_set;
+}
+
+}  // namespace
+
+class IsDirectoryUtilTest : public testing::Test {
+ protected:
+  IsDirectoryUtilTest() {}
+  ~IsDirectoryUtilTest() override {}
+
+  void SetUp() override {
+    EXPECT_TRUE(
+        base::CreateNewTempDirectory(base::FilePath::StringType(), &dir_path_));
+    EXPECT_TRUE(base::CreateTemporaryFile(&file_path_));
+  }
+
+  content::TestBrowserThreadBundle thread_bundle_;
+  TestingProfile profile_;
+  base::FilePath dir_path_;
+  base::FilePath file_path_;
+};
+
+TEST_F(IsDirectoryUtilTest, CollectForEntriesPaths) {
+  std::vector<base::FilePath> paths;
+  paths.push_back(dir_path_);
+  paths.push_back(file_path_);
+  paths.push_back(base::FilePath::FromUTF8Unsafe(kRandomPath));
+
+  IsDirectoryCollector collector(&profile_);
+  std::set<base::FilePath> result;
+  collector.CollectForEntriesPaths(
+      paths, base::Bind(&OnCollectForEntriesPath, &result));
+  content::RunAllBlockingPoolTasksUntilIdle();
+
+  ASSERT_EQ(1u, result.size());
+  EXPECT_GT(result.count(dir_path_), 0u);
+}
+
+}  // namespace app_file_handler_util
+}  // namespace extensions