Suppress AsyncHttpRequestTest.TestCancel leak for LSan

This test fails when run with gtest-parallel on the
ASan bot (that also runs LSan):
http://build.chromium.org/p/client.webrtc.fyi/builders/Linux%20Asan%20%28parallel%29/builds/27

I'm unable to reproduce this locally but it's
obviously failing on the bots.

BUG=4149
R=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/41419004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@8021 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed