Update expectation for a crashing spv175 test.

Crash on trybot:
https://ci.chromium.org/buildbot/tryserver.chromium.mac/mac_chromium_rel_ng/634970

Bug: 805049
Change-Id: If727e7e6bc7e48dff72a0f8d6ae5791e83502725
Reviewed-on: https://chromium-review.googlesource.com/884208
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531768}

third_party/WebKit/LayoutTests/TestExpectations

@@ -87,7 +87,7 @@ crbug.com/771643 virtual/spv175/fast/multicol/mixed-opacity-test.html [ Failure
 crbug.com/771643 virtual/spv175/fast/multicol/multicol-svg.html [ Failure ]
 crbug.com/771643 virtual/spv175/paint/invalidation/svg/absolute-sized-content-with-resources.xhtml [ Failure ]
 
-crbug.com/805049 virtual/spv175/compositing/iframes/fixed-position-iframe.html [ Failure ]
+crbug.com/805049 virtual/spv175/compositing/iframes/fixed-position-iframe.html [ Failure Crash ]
 crbug.com/805049 virtual/spv175/paint/invalidation/compositing/fixed-pos-inside-composited-intermediate-layer.html [ Failure ]
 crbug.com/805049 virtual/spv175/paint/invalidation/compositing/fixed-scroll-in-empty-root-layer.html [ Failure ]
 crbug.com/805049 virtual/spv175/paint/invalidation/scroll/fixed-scroll-simple.html [ Failure ]