mark timeline-recalculate-styles.js as failing on win7

TBR=alph

Bug: 812417
Change-Id: I620e5cf3455b0d40efe1044820cece66e202c670
Reviewed-on: https://chromium-review.googlesource.com/921225Reviewed-by: Tim Schumann <tschumann@chromium.org>
Commit-Queue: Tim Schumann <tschumann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536995}

third_party/WebKit/LayoutTests/TestExpectations

@@ -3220,6 +3220,9 @@ crbug.com/809152 netinfo/estimate-multiple-frames.html [ Pass Failure ]
 crbug.com/810009 [ Linux ] paint/invalidation/image/canvas-composite-repaint-by-all-imagesource.html [ Pass Timeout ]
 crbug.com/810009 [ Linux ] virtual/spv175/paint/invalidation/image/canvas-composite-repaint-by-all-imagesource.html [ Pass Timeout ]
 
+# Sheriff failures 2018-02-15
+crbug.com/812417 [ Win7 ] http/tests/devtools/tracing/timeline-style/timeline-recalculate-styles.js [ Failure ]
+
 # These pass on bots with proprietary codecs (most CQ bots) while failing on bots without.
 crbug.com/807110 external/wpt/html/semantics/embedded-content/media-elements/mime-types/canPlayType.html [ Failure Pass ]
 crbug.com/807110 external/wpt/media-source/mediasource-addsourcebuffer.html [ Failure Pass ]