Add test of animated GIF to power.typical_10_mobile

Add the page
https://en.wikipedia.org/wiki/File:Rotating_earth_(large).gif to the
stories run in power.typical_10_mobile. This tests power usage when an
animated GIF is running slower than chrome's 60fps animation speed.

Bug: 737101
Change-Id: Ica34e8fb78446a2c61069268a502ac5e031649bc
Reviewed-on: https://chromium-review.googlesource.com/1018200Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Commit-Queue: James Wallace-Lee <jamwalla@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553352}

tools/perf/page_sets/data/typical_10_mobile.json

@@ -29,6 +29,9 @@
         },
         "http://www.rg.ru/2014/10/21/cska-site.html": {
             "DEFAULT": "typical_10_mobile_000.wprgo"
+        },
+        "https://en.wikipedia.org/wiki/File:Rotating_earth_(large).gif": {
+            "DEFAULT": "typical_10_mobile_002.wprgo"
         }
     },
     "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating.",

tools/perf/page_sets/data/typical_10_mobile_002.wprgo.sha1

+dede6ce924ce925f46e07abeb2eba2e0156031b9
\ No newline at end of file

tools/perf/page_sets/typical_10_mobile.py

@@ -40,6 +40,8 @@ urls_list = [
     'http://siriuslymeg.tumblr.com/',
     # Why: Popular Chinese language site.
     'http://wapbaike.baidu.com/',
+    # Why: Simple page with an animated GIF
+    'https://en.wikipedia.org/wiki/File:Rotating_earth_(large).gif',
 ]