def _collect_tests(self):
        test_extensions = ['.html', '.svg']

        def _is_test_file(filesystem, dirname, filename):
            return filesystem.splitext(filename)[1] in test_extensions

        filesystem = self._host.filesystem

        paths = []
        for arg in self._args:
            if filesystem.exists(filesystem.join(self._base_path, arg)):
                paths.append(arg)
            else:
                relpath = filesystem.relpath(arg, self._base_path)
                if filesystem.exists(filesystem.join(self._base_path, relpath)):
                    paths.append(filesystem.normpath(relpath))
                else:
                    _log.warn('Path was not found:' + arg)

        skipped_directories = set(['.svn', 'resources'])
        test_files = find_files.find(filesystem, self._base_path, paths, skipped_directories, _is_test_file)
        tests = []
        for path in test_files:
            relative_path = filesystem.relpath(path, self._base_path).replace('\\', '/')
            if self._options.use_skipped_list and self._port.skips_perf_test(relative_path) and filesystem.normpath(relative_path) not in paths:
                continue
            test = PerfTestFactory.create_perf_test(self._port, relative_path, path, test_runner_count=self._options.test_runner_count)
            tests.append(test)

        return tests

    def _collect_tests(self):
        """Return the list of tests found."""

        def _is_test_file(filesystem, dirname, filename):
            return filesystem.splitext(filename)[1] in ['.html', '.svg']

        filesystem = self._host.filesystem

        paths = []
        for arg in self._args:
            paths.append(arg)
            relpath = filesystem.relpath(arg, self._base_path)
            if relpath:
                paths.append(relpath)

        skipped_directories = set(['.svn', 'resources'])
        test_files = find_files.find(filesystem, self._base_path, paths, skipped_directories, _is_test_file)
        tests = []
        for path in test_files:
            relative_path = self._port.relative_perf_test_filename(path).replace('\\', '/')
            if self._port.skips_perf_test(relative_path):
                continue
            tests.append(PerfTestFactory.create_perf_test(relative_path, path))

        return tests