Move reddit to resource_loading_list

This CL moves reddit to resource_loading_list, because reddit has been flakily timing out with a resource load.

Change-Id: I886f418863c1f3a1834441b5215dbd04a5604ba7
Reviewed-on: https://chromium-review.googlesource.com/882643Reviewed-by: Keishi Hattori <keishi@chromium.org>
Commit-Queue: Yuzu Saijo <yuzus@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532317}

tools/perf/contrib/leak_detection/page_sets.py

@@ -56,7 +56,6 @@ class LeakDetectionStorySet(story_module.StorySet):
       'https://www.facebook.com',
       'https://www.baidu.com',
       'https://www.wikipedia.org',
-      'https://www.reddit.com',
       'http://www.qq.com',
       'http://www.amazon.com',
       'http://www.twitter.com',
@@ -74,6 +73,7 @@ class LeakDetectionStorySet(story_module.StorySet):
       'https://www.yahoo.com',
       'http://www.quora.com',
       'https://www.macys.com',
+      'https://www.reddit.com',
     ]
     for url in urls_list:
       self.AddStory(LeakDetectionPage(url, self, url))