Change flaky test to pass on timeout on Win7.

TBR=rockot@chromium.org

Bug: 939289
Change-Id: I86ad8878e2dcd97589425038fdf0ed2871252ee6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1509492Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638737}

third_party/blink/web_tests/TestExpectations

@@ -3187,7 +3187,7 @@ crbug.com/626703 external/wpt/svg/painting/marker-006.svg [ Failure ]
 crbug.com/626703 external/wpt/svg/painting/marker-005.svg [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/css/css-variables/variable-exponential-blowup.html [ Timeout Crash ]
 crbug.com/626703 [ Mac ] external/wpt/css/css-variables/variable-exponential-blowup.html [ Timeout ]
-crbug.com/626703 [ Win ] external/wpt/css/css-variables/variable-exponential-blowup.html [ Crash ]
+crbug.com/626703 [ Win ] external/wpt/css/css-variables/variable-exponential-blowup.html [ Timeout Crash ]
 crbug.com/626703 [ Mac10.13 ] external/wpt/preload/dynamic-adding-preload-imagesrcset.tentative.html [ Timeout ]
 crbug.com/906369 external/wpt/css/css-text/text-transform/text-transform-capitalize-033.html [ Failure ]
 crbug.com/626703 virtual/outofblink-cors/external/wpt/fetch/content-type/response.window.html [ Timeout ]