Add another suppression for 252641

BUG=252641
TBR=zmo@chromium.org

Review URL: https://codereview.chromium.org/472523002

Cr-Commit-Position: refs/heads/master@{#289305}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289305 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/memcheck/suppressions.txt

@@ -5068,6 +5068,15 @@
    ...
    fun:_ZN11leveldb_env19ParseMethodAndErrorEPKcPNS_8MethodIDEPi
 }
+{
+   bug_252641_b
+   Memcheck:Uninitialized
+   fun:pthread_rwlock_init$UNIX2003
+   fun:_ZN3re25MutexC2Ev
+   fun:_ZN3re25MutexC1Ev
+   ...
+   fun:_ZN3gpu12_GLOBAL__N_114StringMismatchERKSsS2_
+}
 {
    bug_253797
    Memcheck:Uninitialized