Removing arena_thread_freeres suppression
Removing arena_thread_freeres suppression

It is no longer needed since we are now using a Chromium revision that
is newer than
http://src.chromium.org/viewvc/chrome?view=rev&revision=172313
In that revision, the arena_thread_freeres suppression was added to
ignore.txt.

BUG=300
TEST=tools/valgrind-webrtc/webrtc_tests.sh --tool=tsan -t
out/Release/system_wrappers_unittests
and trybot execution on linux_tsan

Review URL: https://webrtc-codereview.appspot.com/1019010

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@3375 4adac7df-926f-26a2-2b94-8c16560cd09d

ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc