[css-flex] Remove some flaky test lines from TestExpectations

These don't seem to flake anymore
https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=blink_web_tests&tests=external%2Fwpt%2Fcss%2Fcss-flexbox%2Fflex-minimum-width-flex-items-001.xht%2C%20external%2Fwpt%2Fcss%2Fcss-flexbox%2Fflexbox_flex-natural-mixed-basis-auto.html%2C%20external%2Fwpt%2Fcss%2Fcss-flexbox%2Falign-items-004.htm

Bug: 715718
Change-Id: Id5894cef39174667dc094536fc0749472fbb3936
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2336539
Auto-Submit: David Grogan <dgrogan@chromium.org>
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795063}

third_party/blink/web_tests/TestExpectations

@@ -823,10 +823,6 @@ crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftest
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/flexbox/flexbox-justify-content-vert-006.xhtml [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/flexbox/flexbox-justify-content-wmvert-001.xhtml [ Failure ]
 crbug.com/626703 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/flexbox/flexbox-safe-overflow-position-001.html [ Failure ]
-crbug.com/715718 [ Win ] external/wpt/css/css-flexbox/align-items-004.htm [ Failure Pass ]
-crbug.com/715718 [ Win ] external/wpt/css/css-flexbox/flex-minimum-width-flex-items-001.xht [ Failure Pass ]
-crbug.com/715718 [ Win ] external/wpt/css/css-flexbox/flex-minimum-width-flex-items-003.xht [ Failure Pass ]
-crbug.com/715718 [ Win ] external/wpt/css/css-flexbox/flexbox_flex-natural-mixed-basis-auto.html [ Failure Pass ]
 crbug.com/898186 external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/flexbox/flexbox-intrinsic-ratio-003v.html [ Pass Failure ]
 
 # [css-lists]