sheriff: Disable viewport-unit-transform-responsive.html test

Test keeps timing out on Windows and Linux

TBR=alancutter@chromium.org
NOTRY=true

Bug: 805788
Change-Id: Id1eeb9a0c6629af693131456dc24a5dce532c211
Reviewed-on: https://chromium-review.googlesource.com/885661
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531809}

third_party/WebKit/LayoutTests/TestExpectations

@@ -3391,3 +3391,4 @@ crbug.com/803449 http/tests/devtools/sources/debugger-breakpoints/breakpoints-ui
 # Sheriff failures 2018-01-23
 # Flaking on linux_chromium_rel_ng
 crbug.com/804709 [ Linux ] virtual/gpu/fast/canvas/canvas-fillPath-shadow.html [ Pass Failure ]
+crbug.com/805788 [ Linux Win7 Win10 ] virtual/threaded/animations/responsive/viewport-unit-transform-responsive.html [ Pass Timeout ]