perf: Disable browse:news:nytimes:2020 on mac-10.12

Disabling in memory_desktop + common_desktop for flakiness

TBR: wenbinzhang@google.com
Bug: 1156571
Change-Id: Ic6d78c5ee63cd9bc8486385832084675d083d96b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574986Reviewed-by: Eric Seckler <eseckler@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834687}

tools/perf/expectations.config

@@ -290,6 +290,7 @@ crbug.com/1044682 [ desktop ] system_health.common_desktop/browse:tools:gmail-se
 crbug.com/1044682 [ desktop ] system_health.common_desktop/browse:tools:gmail-compose:2020 [ Skip ]
 crbug.com/1150432 [ linux ] system_health.common_desktop/long_running:tools:gmail-background [ Skip ]
 crbug.com/1154753 [ linux ] system_health.common_desktop/browse:media:imgur [ Skip ]
+crbug.com/1156571 [ mac-10.12 ] system_health.common_desktop/browse:news:nytimes:2020 [ Skip ]
 
 # Benchmark: system_health.common_mobile
 crbug.com/1007355 [ android-go android-webview ] system_health.common_mobile/load:media:imgur:2018 [ Skip ]
@@ -377,6 +378,7 @@ crbug.com/1147969 [ fuchsia ] system_health.memory_desktop/long_running:tools:gm
 crbug.com/1147969 [ fuchsia ] system_health.memory_desktop/multitab:misc:typical24 [ Skip ]
 crbug.com/1147969 [ fuchsia ] system_health.memory_desktop/multitab:misc:typical24:2018 [ Skip ]
 crbug.com/1154753 [ linux ] system_health.memory_desktop/browse:media:imgur [ Skip ]
+crbug.com/1156571 [ mac-10.12 ] system_health.memory_desktop/browse:news:nytimes:2020 [ Skip ]
 
 # Memory dumps don't work at the moment for Google Earth, see the issue.
 crbug.com/1057035 system_health.memory_desktop/browse:tools:earth:2020 [ Skip ]