This test is flaky on the flakiness dashboard, with failures like this:

08:22:43.321 38089 [6008/6079] svg/custom/getscreenctm-in-scrollable-div-area-nested.xhtml failed unexpectedly (text diff, image diff)
08:22:43.320 38132 worker/4 svg/custom/getscreenctm-in-scrollable-div-area-nested.xhtml failed:
08:22:43.320 38132 worker/4  text diff
08:22:43.320 38132 worker/4  image diff

I don't know how to extract the text and image diffs from the bot result.  Here is a sample failed run: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.11%20Tests/28517