Mark external/wpt/webdriver/tests/take_element_screenshot/iframe.py as failing

TBR=foolip@chromium.org

Bug: 1040912
Change-Id: Ie273a75c2f6f7efc1f0b17d9f8325eaaa6e8facf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994296Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730143}

third_party/blink/web_tests/WebDriverExpectations

@@ -161,3 +161,4 @@ crbug.com/626703 [ Linux ] external/wpt/webdriver/tests/perform_actions/key_spec
 crbug.com/626703 [ Linux ] external/wpt/webdriver/tests/new_session/default_values.py>>test_desired [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/webdriver/tests/take_screenshot/user_prompts.py>>test_dismiss_and_notify[capabilities0-alert] [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/webdriver/tests/take_element_screenshot/user_prompts.py>>test_ignore[capabilities0-alert] [ Failure ]
+crbug.com/1023255 [ Linux ] external/wpt/webdriver/tests/take_element_screenshot/iframe.py>>test_frame_element [ Failure Pass ]