Mark element-ready-check-containing-iframe-manual.html passing on Win10.

Attempting to deflake Windows 10 bot.
According to the flakiness dashboard,
external/wpt/fullscreen/api/element-ready-check-containing-iframe-manual.html
now passes consistently. Therefore, removing it from TestExpectations.

TBR=mustaq@chromium.org

Bug: 908841, 954586
Change-Id: Ia51a032a5470454527eefab570c61d57caa73d88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1575165
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652643}

third_party/blink/web_tests/TestExpectations

@@ -24,9 +24,6 @@ crbug.com/906791 external/wpt/fullscreen/api/element-ready-check-allowed-cross-o
 crbug.com/860713 external/wpt/bluetooth/requestDevice/cross-origin-iframe.sub.https.html [ Failure Timeout ]
 crbug.com/860713 external/wpt/bluetooth/requestDevice/request-from-sandboxed-iframe.https.html [ Failure Timeout ]
 
-# The following tests passes only with User Activation v2 (UAv2) disabled.
-crbug.com/908841 external/wpt/fullscreen/api/element-ready-check-containing-iframe-manual.html [ Timeout ]
-
 # The following tests fail with UserActivationSameOriginVisibility plus UAv2.
 crbug.com/922725 external/wpt/fullscreen/api/element-ready-check-containing-iframe-manual.tentative.html [ Failure ]
 crbug.com/922725 external/wpt/html/user-activation/activation-api-iframe-no-activate.tenative.html [ Failure ]