Remove flaky expectation for images/image-hover-display-alt.html

TBR: fmalita@chromium.org
Bug: 831183
Change-Id: Ieecb1a075022c212999f0f2306360a7eca745f8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1734756Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683884}

third_party/blink/web_tests/TestExpectations

@@ -5524,9 +5524,6 @@ crbug.com/941429 virtual/gpu/fast/canvas/canvas-ellipse-circumference.html [ Fai
 # Sheriff 2018-05-31
 crbug.com/848398 http/tests/devtools/oopif/oopif-performance-cpu-profiles.js [ Pass Timeout Failure ]
 
-# Sheriff 2018-06-01
-crbug.com/848851 virtual/exotic-color-space/images/image-hover-display-alt.html [ Failure Pass ]
-
 # Flakes 2018-06-02
 crbug.com/841567 fast/scrolling/scrollbar-tickmarks-hittest.html [ Failure Pass ]