Disabling v8.browing_desktop-future/browse:tech:discourse_infinite_scroll

on mac 10.12

TBR=charliea@chromium.org
NOTRY=true

Bug: 805934
Change-Id: Ifc2da35f001c146e59836e32e60a168ea063ec66
Reviewed-on: https://chromium-review.googlesource.com/887221Reviewed-by: Emily Hanley <eyaich@chromium.org>
Commit-Queue: Emily Hanley <eyaich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531941}

tools/perf/expectations.config

@@ -305,6 +305,7 @@ crbug.com/676336 [ Mac ] v8.browsing_desktop-future/browse:news:hackernews [ Ski
 crbug.com/728576 [ Mac ] v8.browsing_desktop-future/browse:news:cnn [ Skip ]
 crbug.com/798465 [ Mac ] v8.browsing_desktop-future/browse:news:flipboard [ Skip ]
 crbug.com/798465 [ Win ] v8.browsing_desktop-future/browse:news:flipboard [ Skip ]
+crbug.com/805934 [ Mac_10.12 ] v8.browsing_desktop-future/browse:tech:discourse_infinite_scroll [ Skip ]
 
 # Benchmark: v8.browsing_mobile
 crbug.com/788797 [ Cherry_Mobile_Android_One ] v8.browsing_mobile/browse:social:facebook_infinite_scroll [ Skip ]