Adding TestExpectation for flaky webkit_layout_test

TBR: sullivan@chromium.org
Bug: 1041709
Change-Id: Ie993df88a7ab5261659b9f1e04236cbb24df5a61
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024121Reviewed-by: Joe Downing <joedow@chromium.org>
Commit-Queue: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735668}

third_party/blink/web_tests/TestExpectations

@@ -761,6 +761,7 @@ crbug.com/591099 virtual/mouseevent_fractional/fast/events/touch/compositor-touc
 crbug.com/591099 virtual/mouseevent_fractional/fast/events/touch/compositor-touch-hit-rects.html [ Failure ]
 crbug.com/591099 external/wpt/paint-timing/sibling-painting-first-image.html [ Failure ]
 crbug.com/591099 virtual/paint-timing/external/wpt/paint-timing/sibling-painting-first-image.html [ Failure ]
+crbug.com/1041709 [ Linux Debug ] external/wpt/paint-timing/first-image-child.html [ Pass Timeout ]
 crbug.com/591099 virtual/scalefactor200/css3/filters/composited-layer-child-bounds-after-composited-to-sw-shadow-change.html [ Failure ]
 
 # LayoutNG ref-tests that need to be updated (cannot be rebaselined).