TSAN: Suppress error in ThreadWatcher::StartWatching.

BUG=83564
TEST=none
TBR=timurrrr
Review URL: http://codereview.chromium.org/6990032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86256 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/tsan/suppressions.txt

@@ -132,6 +132,14 @@
   fun:syncable::BaseTransaction::NotifyTransactionChangingAndEnding
 }
 
+{
+  bug_83564
+  ThreadSanitizer:Race
+  fun:base::Thread::message_loop
+  fun:BrowserThread::IsMessageLoopValid
+  fun:ThreadWatcherList::StartWatchingAll
+}
+
 ############################
 # Benign races in Chromium
 {