Mark controls-video-keynav.html as failing.

This is also failing on Win7 Debug along with the other video tests.
They both seem flaky, so likely have the same root cause.

BUG=746128
TBR=johnme@chromium.org

Change-Id: I3622dc76166bc229222f4966eb2bafcfac7de0f1
Reviewed-on: https://chromium-review.googlesource.com/582470Reviewed-by: Ojan Vafai <ojan@chromium.org>
Commit-Queue: Ojan Vafai <ojan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488839}

third_party/WebKit/LayoutTests/TestExpectations

@@ -3126,6 +3126,7 @@ crbug.com/626703 [ Win7 ] external/wpt/html/syntax/parsing/html5lib_tests16.html
 
 crbug.com/746128 [ Win7 Debug ] media/controls/video-enter-exit-fullscreen-without-hovering-doesnt-show-controls.html [ Failure ]
 crbug.com/746128 [ Win7 Debug ] virtual/new-remote-playback-pipeline/media/controls/video-enter-exit-fullscreen-without-hovering-doesnt-show-controls.html [ Failure ]
+crbug.com/746128 [ Win7 Debug ] virtual/new-remote-playback-pipeline/media/controls/controls-video-keynav.html [ Failure ]
 
 crbug.com/626703 [ Win7 ] external/wpt/image-decodes/image-decode-path-changes.html [ Pass Crash ]