Re-enable the detached.tentative.window test

The bug that caused flakiness was fixed.

Bug: 1097332
Change-Id: I26b741a59244ad46121ec5738955a6f607dea2c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2259843Reviewed-by: Anatoliy Potapchuk <apotapchuk@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781462}

third_party/blink/web_tests/TestExpectations

@@ -405,9 +405,6 @@ crbug.com/1050993 [ Linux ] virtual/gpu-rasterization/images/drag-image-descenda
 # Flaky test.
 crbug.com/1054894 http/tests/images/image-decode-in-frame.html [ Pass Timeout ]
 
-# Flaky test.
-crbug.com/1097332 external/wpt/measure-memory/detached.tentative.window.html [ Pass Failure ]
-
 # ====== Paint team owned tests to here ======
 
 crbug.com/922249 virtual/android/fullscreen/compositor-touch-hit-rects-fullscreen-video-controls.html [ Failure Pass ]