Add load_accessibility:media:wikipedia:2018 story

Bug: 878390
Change-Id: I94ff2c90bca4434f311b042d3265df881ad8f69e
Reviewed-on: https://chromium-review.googlesource.com/1222695
Commit-Queue: James Wallace-Lee <jamwalla@chromium.org>
Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593219}

tools/perf/page_sets/data/system_health_desktop.json

@@ -213,6 +213,9 @@
         "load_accessibility:media:wikipedia": {
             "DEFAULT": "system_health_desktop_059.wprgo"
         },
+        "load_accessibility:media:wikipedia:2018": {
+            "DEFAULT": "system_health_desktop_6903b36338.wprgo"
+        },
         "load_accessibility:shopping:amazon": {
             "DEFAULT": "system_health_desktop_059.wprgo"
         },

tools/perf/page_sets/data/system_health_desktop_6903b36338.wprgo.sha1

+6903b36338b00527168448c654c65842ebaa4b20
\ No newline at end of file

tools/perf/page_sets/system_health/accessibility_stories.py

@@ -56,6 +56,11 @@ class AccessibilityWikipediaStory(_AccessibilityStory):
   URL = 'https://en.wikipedia.org/wiki/Accessibility'
   TAGS = [story_tags.ACCESSIBILITY, story_tags.YEAR_2016]
 
+class AccessibilityWikipediaStory2018(_AccessibilityStory):
+  """Wikipedia page on Accessibility. Long, but very simple, clean layout."""
+  NAME = 'load_accessibility:media:wikipedia:2018'
+  URL = 'https://en.wikipedia.org/wiki/Accessibility'
+  TAGS = [story_tags.ACCESSIBILITY, story_tags.YEAR_2018]
 
 class AccessibilityAmazonStory(_AccessibilityStory):
   """Amazon results page. Good example of a site with a data table."""