Disable external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-animation.html for mac

TBR=layout-dev@chromium.org
No-Presubmit: true
No-Tree-Checks: true
No-Try: true

Bug: 626703
Change-Id: Ifda3ec2fd9307c57a8f9c3e3a6192d76c294a032
Fixed: 1044858
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2015914Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734361}

third_party/blink/web_tests/TestExpectations

@@ -2799,7 +2799,7 @@ crbug.com/641245 external/wpt/css/motion/offset-path-ray-contain-004.html [ Fail
 crbug.com/641245 external/wpt/css/motion/offset-path-ray-contain-005.html [ Failure ]
 
 # ====== New tests from wpt-importer added here ======
-crbug.com/626703 [ Mac10.11 ] external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-animation.html [ Failure ]
+crbug.com/626703 [ Mac ] external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-animation.html [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-canvas-parent.html [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-canvas-sibling.html [ Failure ]
 crbug.com/626703 [ Linux ] external/wpt/css/compositing/mix-blend-mode/mix-blend-mode-parent-with-border-radius.html [ Failure ]