Mark http/tests/media/video-play-stall.html as flaky

third_party/WebKit/LayoutTests/TestExpectations

Index: third_party/WebKit/LayoutTests/TestExpectations
diff --git a/third_party/WebKit/LayoutTests/TestExpectations b/third_party/WebKit/LayoutTests/TestExpectations
index 4fd429410874710c540b4742e8562ebd56a574cc..2d9b12e3fc1185b641db40094d9cae97be9a99b7 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations
@@ -2547,10 +2547,9 @@ crbug.com/688515 fast/spatial-navigation/snav-div-overflow-scrol-hidden.html [ P
 crbug.com/688486 external/wpt/service-workers/service-worker/fetch-request-redirect.https.html [ Failure Pass ]
 crbug.com/688486 external/wpt/service-workers/service-worker/fetch-request-resources.https.html [ Failure Pass ]
 
-# Sheriff failures 2017-02-06
-crbug.com/688515 [ Linux ] http/tests/media/video-play-stall.html [ Pass Failure ]
-
 # Sheriff failures 2017-02-13
 crbug.com/691423 [ Mac ] fast/frames/location-change-no-file-access.html [ Failure Pass ]
 
-# Sheriff failures 2017-02-16
+# Sheriff failures 2017-02-21
+crbug.com/73609 http/tests/media/video-play-stall.html [ Pass Timeout ]
+crbug.com/73609 virtual/mojo-loading/http/tests/media/video-play-stall.html [ Pass Timeout ]