Cookie Store API: Remove flaky test expectations.

We expect https://crrev.com/c/1635430 to have fixed the flakiness and
manually confirmed that the test now passes across 100 repeated runs.

Bug: 827231
Change-Id: I4599671cf6db1192847585ba2789995b377d23aa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1696449
Commit-Queue: Staphany Park <staphany@chromium.org>
Auto-Submit: Staphany Park <staphany@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676343}

third_party/blink/web_tests/TestExpectations

@@ -5169,10 +5169,6 @@ crbug.com/783800 external/wpt/imagecapture/MediaStreamTrack-applyConstraints-get
 crbug.com/783301 external/wpt/imagecapture/MediaStreamTrack-getSettings.html [ Pass Failure ]
 crbug.com/783301 external/wpt/imagecapture/MediaStreamTrack-getCapabilities.html [ Pass Failure ]
 
-# Cookie Store API
-crbug.com/827231 external/wpt/cookie-store/document_cookie.tentative.html [ Pass Failure ]
-crbug.com/827231 external/wpt/cookie-store/document_cookie.tentative.https.html [ Pass Failure ]
-
 # Failing SameSite cookies tests
 crbug.com/843945 external/wpt/cookies/samesite/form-get-blank-reload.html [ Failure ]
 crbug.com/843945 external/wpt/cookies/samesite/form-post-blank-reload.html [ Failure ]