Disable failing tumblr_infinite_scroll:2018 telemetry_unittests

Flaky on Windows and Mac platforms.

TBR=crouleau@chromium.org

BUG: 1027902
Change-Id: I354fd7411f1c7e65748550fcc297f576f0753e46
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1932656
Commit-Queue: Tim Schumann <tschumann@chromium.org>
Reviewed-by: Tim Schumann <tschumann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718455}

tools/perf/expectations.config

@@ -329,6 +329,8 @@ crbug.com/1014655 [ android-webview ] system_health.common_mobile/browse:social:
 
 # Benchmark: system_health.memory_desktop
 crbug.com/1027686 [ linux ] system_health.memory_desktop/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
+crbug.com/1027902 [ win ] system_health.memory_desktop/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
+crbug.com/1027902 [ mac ] system_health.memory_desktop/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
 crbug.com/984599 [ linux ] system_health.memory_desktop/long_running:tools:gmail-foreground [ Skip ]
 crbug.com/984599 [ mac ] system_health.memory_desktop/long_running:tools:gmail-background [ Skip ]
 crbug.com/1000426 [ win ] system_health.memory_desktop/long_running:tools:gmail-background [ Skip ]