message: Avoid crashing tests when a file or directory deletion fails
diff: @@ -33,16 +33,22 @@ bool NO_FAIL(unique_ptr<QueryResult> result) {
  void TestDeleteDirectory(string path) {
  unique_ptr<FileSystem> fs = FileSystem::CreateLocal();
  + try {
  if (fs->DirectoryExists(path)) {
  fs->RemoveDirectory(path);
  }
  + } catch (...) {
  + }
  }
  void TestDeleteFile(string path) {
  unique_ptr<FileSystem> fs = FileSystem::CreateLocal();
  + try {
  if (fs->FileExists(path)) {
  fs->RemoveFile(path);
  }
  + } catch (...) {
  + }
  }
  void TestChangeDirectory(string path) {
  