Mark two CSS font tests also failing on Mac 10.13

The two tests rely on CoreText's OpenType feature support. They were
previously identified as failing on Mac 10.12. After being tried on Mac
10.13, they still fail.

No-Try: True
Bug: 774301, 752449
Change-Id: If0cc92a6896e47cadae863a026f2f97770b68cf8
Reviewed-on: https://chromium-review.googlesource.com/881768Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532436}

third_party/WebKit/LayoutTests/TestExpectations

@@ -1430,8 +1430,8 @@ crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-c
 crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-006a.html [ Failure Pass ]
 crbug.com/736319 [ Linux Mac ] external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/writing-modes-3/text-combine-upright-compression-007.html [ Failure Pass ]
 
-crbug.com/752449 [ Mac10.12 ] external/wpt/css/css-fonts/matching/fixed-stretch-style-over-weight.html [ Failure ]
-crbug.com/752449 [ Mac10.12 ] external/wpt/css/css-fonts/matching/stretch-distance-over-weight-distance.html [ Failure ]
+crbug.com/752449 [ Mac10.12 Mac10.13 ] external/wpt/css/css-fonts/matching/fixed-stretch-style-over-weight.html [ Failure ]
+crbug.com/752449 [ Mac10.12 Mac10.13 ] external/wpt/css/css-fonts/matching/stretch-distance-over-weight-distance.html [ Failure ]
 crbug.com/752449 [ Mac10.12 ] external/wpt/css/css-fonts/matching/style-ranges-over-weight-direction.html [ Failure ]
 crbug.com/796619 [ Win10 ] external/wpt/css/css-fonts/matching/fixed-stretch-style-over-weight.html [ Failure ]
 crbug.com/796619 [ Win10 ] external/wpt/css/css-fonts/matching/stretch-distance-over-weight-distance.html [ Failure ]