[ChromeDriver] Re-enable new window test on Android

Re-enable ChromeDriverTest.testShouldHandleNewWindowLoadingProperly
on Android. It no logner appears to be flaky.

Bug: chromedriver:1478
Change-Id: Ia573dca0799b973b0a09ec16508cc3b667774e11
Reviewed-on: https://chromium-review.googlesource.com/1028365Reviewed-by: Jonathon Kereliuk <kereliuk@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554772}

chrome/test/chromedriver/test/run_py_tests.py

@@ -239,8 +239,6 @@ _ANDROID_NEGATIVE_FILTER['chromium'] = (
         'ChromeDriverTest.testShadowDomHover',
         'ChromeDriverTest.testMouseMoveTo',
         'ChromeDriverTest.testHoverOverElement',
-        # https://bugs.chromium.org/p/chromedriver/issues/detail?id=1478
-        'ChromeDriverTest.testShouldHandleNewWindowLoadingProperly',
         # https://bugs.chromium.org/p/chromedriver/issues/detail?id=2388
         'ChromeDriverTest.testTouchDoubleTapElement',
         'ChromeDriverTest.testTouchLongPressElement',