Fix download filename tests

If we want the same restrictive escaping in existing downloads, we'll need to
simulate Windows.

tests/unit/browser/webkit/test_downloads.py

@@ -62,6 +62,7 @@ def test_download_model(qapp, qtmodeltester, config_stub, cookiejar_and_cache,
      '',
      None),
 ])
+@pytest.mark.fake_os('windows')
 def test_page_titles(url, title, out):
     assert downloads.suggested_fn_from_title(url, title) == out
 

tests/unit/utils/test_utils.py

@@ -649,6 +649,7 @@ def test_sanitize_filename(inp, expected, monkeypatch):
     assert utils.sanitize_filename(inp) == expected
 
 
+@pytest.mark.fake_os('windows')
 def test_sanitize_filename_empty_replacement():
     name = '/<Bad File>/'
     assert utils.sanitize_filename(name, replacement=None) == 'Bad File'