Add missing entry in LeakExpectations

Bug: 910211
Change-Id: I32512c338b59e5474a89b32172e2089f96467598
TBR: sebsg@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1355491Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612272}

third_party/blink/web_tests/LeakExpectations

@@ -87,6 +87,7 @@ crbug.com/878727 [ Linux ] virtual/threaded/http/tests/devtools/tracing/timeline
 crbug.com/862029 [ Linux ] virtual/threaded/http/tests/devtools/tracing/timeline-misc/timeline-window-filter.js [ Pass Leak ]
 
 crbug.com/733494 [ Linux ] media/autoplay/document-user-activation.html [ Pass Leak ]
+crbug.com/733494 [ Linux ] virtual/video-surface-layer/media/autoplay/document-user-activation.html [ Pass Leak ]
 
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 # WARNING: Memory leaks must be fixed asap. Sheriff is expected to revert #