tools/perf: Disable blink_perf.parser.declarative-shadow-dom-cloning on Mac

NOTRY=true
TBR=masonfreed@chromium.org

Bug: 1147058
Change-Id: Ica80747af140f1c1eddff795fd14c709314647ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2526069Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Commit-Queue: Sami Kyöstilä <skyostil@chromium.org>
Auto-Submit: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825352}

tools/perf/expectations.config

@@ -65,6 +65,7 @@ crbug.com/966913 [ android-nexus-5x android-webview ] blink_perf.parser/query-se
 crbug.com/966613 [ android-pixel-2 ] blink_perf.parser/query-selector-all-class-deep.html [ Skip ]
 crbug.com/966613 [ android-pixel-2 ] blink_perf.parser/query-selector-all-deep.html [ Skip ]
 crbug.com/966613 [ android-pixel-2 ] blink_perf.parser/query-selector-all-id-deep.html [ Skip ]
+crbug.com/1147058 [ mac ] blink_perf.parser/declarative-shadow-dom-cloning.html [ Skip ]
 
 # Benchmark: blink_perf.shadow_dom
 crbug.com/702319 [ android-nexus-5x ] blink_perf.shadow_dom/* [ Skip ]