Revert "Mark several text layout tests as failing on Mac"

This reverts commit 1841a794.

Reason for revert: HarfBuzz roll which caused test failures has already been reverted. https://chromium-review.googlesource.com/c/chromium/src/+/1439970

Original change's description:
> Mark several text layout tests as failing on Mac
> 
> fast/text/atsui-spacing-features.html
> fast/text/emphasis-complex.html
> fast/text/international/hebrew-vowels.html
> svg/text/combining-character-queries.html
> svg/text/ligature-queries.html
> svg/text/surrogate-pair-queries.html
> 
> TBR=drott@chromium.org
> 
> Bug: 925866
> Change-Id: Iafb0f31852b96c46a725e404e85debd875d96ed5
> Reviewed-on: https://chromium-review.googlesource.com/c/1440021
> Reviewed-by: Kevin McNee <mcnee@chromium.org>
> Commit-Queue: Kevin McNee <mcnee@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#626634}

TBR=drott@chromium.org,mcnee@chromium.org

Change-Id: Icb43a6d325a0b2a63f9e61d2e1a451960aaa3d6a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 925866
Reviewed-on: https://chromium-review.googlesource.com/c/1442251Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626914}

third_party/blink/web_tests/TestExpectations

@@ -5869,22 +5869,3 @@ crbug.com/924670 external/wpt/webvr/webvr-supported-by-feature-policy.html [ Fai
 
 # Sheriff 2019-01-25
 crbug.com/925325 [ Mac ] storage/indexeddb/index-population.html [ Pass Failure ]
-
-# Sheriff 2019-01-28
-crbug.com/925866 [ Mac10.10 ] fast/text/atsui-spacing-features.html [ Failure ]
-crbug.com/925866 [ Mac10.10 ] fast/text/emphasis-complex.html [ Failure ]
-crbug.com/925866 [ Mac10.10 ] fast/text/international/hebrew-vowels.html [ Failure ]
-crbug.com/925866 [ Mac10.10 ] svg/text/combining-character-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.10 ] svg/text/ligature-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] fast/text/atsui-spacing-features.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] fast/text/emphasis-complex.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] fast/text/international/hebrew-vowels.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] svg/text/combining-character-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] svg/text/ligature-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.11 ] svg/text/surrogate-pair-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] fast/text/atsui-spacing-features.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] fast/text/emphasis-complex.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] fast/text/international/hebrew-vowels.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] svg/text/combining-character-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] svg/text/ligature-queries.html [ Failure ]
-crbug.com/925866 [ Mac10.12 ] svg/text/surrogate-pair-queries.html [ Failure ]