Revert of Remove oilevent from tough layout cases. (https://codereview.chromium.org/234813010/)

Reason for revert:
Did not fix OOM, just moved it.

BUG=357326

Original issue's description:
> Remove oilevent from tough layout cases.
> 
> It OOMs on some android devices now and no one has the cycles to debug.
> 
> BUG=357326
> NOTRY=True
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266039

TBR=simonhatch@chromium.org,rschoen@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=357326

Review URL: https://codereview.chromium.org/252703005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266257 0039d316-1c4b-4281-b951-d872f2087c98

tools/perf/page_sets/tough_layout_cases.py

@@ -32,6 +32,7 @@ class ToughLayoutCasesPageSet(page_set_module.PageSet):
       archive_data_file='data/tough_layout_cases.json')
 
     urls_list = [
+      'http://oilevent.com',
       'http://www.muzoboss.ru',
       'http://natunkantha.com',
       'http://www.mossiella.com',