Disable flaky perf tests */browse:news:hackernews:2018

Disable three perf tests that are flaky on the desktop:
* system_health.common_desktop/browse:news:hackernews:2018
* v8.browsing_desktop-future/browse:news:hackernews:2018
* v8.browsing_desktop/browse:news:hackernews:2018

TBR=crouleau@chromium.org
NOTRY=true

Bug: 1008028
Change-Id: Icd3f51a3eaa7e1aa2cd01517c62acfece62c0151
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1825570Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699857}

tools/perf/expectations.config

@@ -302,6 +302,7 @@ crbug.com/911214 [ win ] system_health.common_desktop/multitab:misc:typical24 [
 crbug.com/934270 [ win ] system_health.common_desktop/multitab:misc:typical24:2018 [ Skip ]
 crbug.com/931185 [ win7 ] system_health.common_desktop/browse:media:youtubetv:2019 [ Skip ]
 crbug.com/958422 [ win7 ] system_health.common_desktop/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
+crbug.com/1008028 [ desktop ] system_health.common_desktop/browse:news:hackernews:2018 [ Skip ]
 
 # Benchmark: system_health.common_mobile
 crbug.com/914390 [ android-nexus-5 ] system_health.common_mobile/browse:chrome:newtab [ Skip ]
@@ -402,6 +403,7 @@ crbug.com/954959 [ linux ] v8.browsing_desktop/browse:media:pinterest:2018 [ Ski
 crbug.com/954959 [ linux ] v8.browsing_desktop/browse:tools:maps [ Skip ]
 crbug.com/958422 v8.browsing_desktop/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
 crbug.com/958507 [ desktop ] v8.browsing_desktop/browse:media:imgur [ Skip ]
+crbug.com/1008028 [ desktop ] v8.browsing_desktop/browse:news:hackernews:2018 [ Skip ]
 
 # Benchmark v8.browsing_desktop-future
 crbug.com/788796 [ linux ] v8.browsing_desktop-future/browse:media:imgur [ Skip ]
@@ -411,6 +413,7 @@ crbug.com/906654 v8.browsing_desktop-future/browse:search:google [ Skip ]
 crbug.com/953371 [ win ] v8.browsing_desktop-future/browse:social:twitter_infinite_scroll:2018 [ Skip ]
 crbug.com/958422 v8.browsing_desktop-future/browse:social:tumblr_infinite_scroll:2018 [ Skip ]
 crbug.com/958507 [ desktop ] v8.browsing_desktop-future/browse:media:imgur [ Skip ]
+crbug.com/1008028 [ desktop ] v8.browsing_desktop-future/browse:news:hackernews:2018 [ Skip ]
 
 # Benchmark: v8.browsing_mobile
 crbug.com/958034 [ android-go android-webview ] v8.browsing_mobile/* [ Skip ]