message: Fix the compilation problem of HDFS test cases
diff: @@ -121,12 +121,12 @@ TEST_F(HadoopFileSystemTest, FileExists) {
  TEST_F(HadoopFileSystemTest, GetChildren) {
  const string base = TmpDir("GetChildren");
  - TF_EXPECT_OK(hdfs.CreateDir(base));
  + TF_EXPECT_OK(hdfs.CreateDir(base, nullptr));
  const string file = io::JoinPath(base, "testfile.csv");
  TF_EXPECT_OK(WriteString(file, "blah"));
  const string subdir = io::JoinPath(base, "subdir");
  - TF_EXPECT_OK(hdfs.CreateDir(subdir));
  + TF_EXPECT_OK(hdfs.CreateDir(subdir, nullptr));
  std::vector<string> children;
  TF_EXPECT_OK(hdfs.GetChildren(base, &children));
  @@ -151,7 +151,7 @@ TEST_F(HadoopFileSystemTest, GetFileSize) {
  TEST_F(HadoopFileSystemTest, CreateDirStat) {
  const string dir = TmpDir("CreateDirStat");
  - TF_EXPECT_OK(hdfs.CreateDir(dir));
  + TF_EXPECT_OK(hdfs.CreateDir(dir, nullptr));
  FileStatistics stat;
  TF_EXPECT_OK(hdfs.Stat(dir, &stat));
  EXPECT_TRUE(stat.is_directory);
  @@ -160,7 +160,7 @@ TEST_F(HadoopFileSystemTest, CreateDirStat) {
  TEST_F(HadoopFileSystemTest, DeleteDir) {
  const string dir = TmpDir("DeleteDir");
  EXPECT_FALSE(hdfs.DeleteDir(dir).ok());
  - TF_EXPECT_OK(hdfs.CreateDir(dir));
  + TF_EXPECT_OK(hdfs.CreateDir(dir, nullptr));
  TF_EXPECT_OK(hdfs.DeleteDir(dir));
  FileStatistics stat;
  EXPECT_FALSE(hdfs.Stat(dir, &stat).ok());
  