Skip video-surface-layer version of document-user-activation.html on Linux

It fails with the leak detector. The version without the
"virtual/video-surface-layer/" prefix was already being skipped.

TBR=mlamouri@chromium.org

Bug: 838128
Change-Id: Icb4e898e9c24c20b94cd5bfb51042b65e1ace7d4
Reviewed-on: https://chromium-review.googlesource.com/1043865Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556015}

third_party/WebKit/LayoutTests/TestExpectations

@@ -2527,6 +2527,7 @@ crbug.com/491764 http/tests/devtools/service-workers/user-agent-override.js [ Pa
 
 # Fails with leak detector.
 crbug.com/733494 [ Linux ] media/autoplay/document-user-activation.html [ Skip ]
+crbug.com/733494 [ Linux ] virtual/video-surface-layer/media/autoplay/document-user-activation.html [ Skip ]
 crbug.com/769885 [ Linux ] virtual/android/fullscreen/full-screen-frameset.html [ Skip ]