Disable failing system_health.memory_mobile/browse:chrome:newtab.

Bug: 914390
Change-Id: Ib8d55b5782dd17b280440e87117654b5ede876be
TBR: charliea@chromium.org
NOTRY: true
Reviewed-on: https://chromium-review.googlesource.com/c/1374198Reviewed-by: Annie Sullivan <sullivan@chromium.org>
Commit-Queue: Annie Sullivan <sullivan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615913}

tools/perf/expectations.config

@@ -246,6 +246,7 @@ crbug.com/903417 [ Mac ] system_health.common_desktop/long_running:tools:gmail-f
 crbug.com/903417 [ Win ] system_health.common_desktop/long_running:tools:gmail-foreground [ Skip ]
 
 # Benchmark: system_health.common_mobile
+crbug.com/914390 [ Nexus_5 ] system_health.memory_mobile/browse:chrome:newtab [ Skip ]
 crbug.com/714650 [ Android ] system_health.common_mobile/browse:news:globo [ Skip ]
 crbug.com/787001 [ Android_Webview ] system_health.common_mobile/load:media:soundcloud [ Skip ]
 crbug.com/708300 [ Android ] system_health.common_mobile/browse:shopping:flipkart [ Skip ]
@@ -280,7 +281,7 @@ crbug.com/899887 [ Linux ] system_health.memory_desktop/browse:social:facebook_i
 
 # Benchmark: system_health.memory_mobile
 crbug.com/787001 [ Android_Webview ] system_health.memory_mobile/load:media:soundcloud [ Skip ]
-[ Android_Webview ] system_health.memory_mobile/browse:chrome:newtab [ Skip ]
+crbug.com/914390 [ Android_Webview Nexus_5 ] system_health.memory_mobile/browse:chrome:newtab [ Skip ]
 crbug.com/714650 [ Android ] system_health.memory_mobile/browse:news:globo [ Skip ]
 [ Android_Webview ] system_health.memory_mobile/browse:chrome:omnibox [ Skip ]
 crbug.com/819552 [ Nexus_5X ] system_health.memory_mobile/browse:chrome:omnibox [ Skip ]