Mark get-persistendeviceid-from-pointer-event.tentative.html as flaky

This has become a top-flake (P1) recently w/o any relevant code change
we are aware of!

Bug: 446116790
Change-Id: I5f48ccd58140eed65739e2dcc31e5d311cab599a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6968969
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Reviewed-by: David Awogbemila <awogbemila@chromium.org>
Commit-Queue: David Awogbemila <awogbemila@chromium.org>
Auto-Submit: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1517947}
diff --git a/third_party/blink/web_tests/TestExpectations b/third_party/blink/web_tests/TestExpectations
index b93c91d..90b0be4 100644
--- a/third_party/blink/web_tests/TestExpectations
+++ b/third_party/blink/web_tests/TestExpectations
@@ -8384,6 +8384,7 @@
 crbug.com/41493566 [ Mac14-arm64 ] http/tests/security/frameNavigation/xss-ALLOWED-top-navigation-after-postMessage.html [ Failure Pass ]
 
 crbug.com/626703 [ Mac ] external/wpt/pointerevents/pointerevent_after_target_appended.html?mouse [ Failure Timeout ]
+crbug.com/446116790 [ Linux ] external/wpt/pointerevents/persistentDeviceId/get-persistendeviceid-from-pointer-event.tentative.html [ Failure Pass ]
 
 # Mac15/arm64 - Flaky tests
 [ Mac15 ] external/wpt/css/css-content/quotes-020.html [ Failure ]  # Reftest image failure