[tools/perf/contrib] Fix PinterestJankyStory

Change-Id: Ia2333c6856de7e9bb8ff1ddd26fba3d0af62d6f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2112358Reviewed-by: Stephen Nusko <nuskos@chromium.org>
Commit-Queue: Mikhail Khokhlov <khokhlov@google.com>
Cr-Commit-Position: refs/heads/master@{#751998}

tools/perf/contrib/system_health_infinite_scroll/janky_story_set.py

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 from page_sets.helpers import override_online
+from page_sets.login_helpers import pinterest_login
 from page_sets.system_health import platforms
 from page_sets.system_health import story_tags
 from page_sets.system_health import system_health_story
@@ -59,6 +60,11 @@ class PinterestJankyStory(JankyStory):
   URL = 'https://www.pinterest.co.uk'
   TAGS = [story_tags.INFINITE_SCROLL, story_tags.YEAR_2019]
 
+  SKIP_LOGIN = False
+
+  def _Login(self, action_runner):
+    pinterest_login.LoginMobileAccount(action_runner, 'googletest')
+
 
 class TumblrJankyStory(JankyStory):
   NAME = 'browse:social:tumblr_infinite_scroll:2018'