[perf] Add load:news:nytimes:2018 system health story

Bug: 878390
Change-Id: I7dd274d816f8833bdabe890628b92f701612ffed
Reviewed-on: https://chromium-review.googlesource.com/c/1264659Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597532}

tools/perf/page_sets/data/system_health_desktop.json

@@ -156,6 +156,9 @@
         "load:news:nytimes": {
             "DEFAULT": "system_health_desktop_009.wprgo"
         },
+        "load:news:nytimes:2018": {
+            "DEFAULT": "system_health_desktop_6d7605317e.wprgo"
+        },
         "load:news:qq": {
             "DEFAULT": "system_health_desktop_010.wprgo"
         },

tools/perf/page_sets/data/system_health_desktop_6d7605317e.wprgo.sha1

+6d7605317ea18a366c29a0bfb9d7ce525852f03d
\ No newline at end of file

tools/perf/page_sets/system_health/loading_stories.py

@@ -184,6 +184,13 @@ class LoadNytimesDesktopStory(_LoadingStory):
   SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
 
 
+class LoadNytimesDesktopStory2018(_LoadingStory):
+  NAME = 'load:news:nytimes:2018'
+  URL = 'http://www.nytimes.com'
+  TAGS = [story_tags.YEAR_2018]
+  SUPPORTED_PLATFORMS = platforms.DESKTOP_ONLY
+
+
 class LoadNytimesMobileStory(_LoadingStory):
   NAME = 'load:news:nytimes'
   URL = 'http://mobile.nytimes.com'