Add one more suppression rule for tracked_objects.

tools/valgrind/memcheck/suppressions_mac.txt

 # There are three kinds of suppressions in this file:
 # 1. Third party stuff we have no control over.
 #
 # 2. Intentional unit test errors, stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing.
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system.
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1925 matching lines @@
    fun:_ZNK12TCGFontCache8CopyFontEPK7__CFURL
    fun:_ZNK9TBaseFont14CopyNativeFontEv
    fun:_ZNK9TBaseFont20CalculateFontMetricsEb
    fun:_ZNK9TBaseFont15InitFontMetricsEv
    fun:_ZNK9TBaseFont16GetStrikeMetricsEfPK17CGAffineTransformb
    fun:_ZNK5TFont17InitStrikeMetricsEv
    fun:CTFontGetAscent
    fun:__NSFontInstanceInfoInitializeMetricsInfo
 }
 {
-   bug_102327
+   bug_102327_a
    Memcheck:Addr1
    fun:_ZNK15tracked_objects10ThreadData26OnThreadTerminationCleanupEv
    fun:_ZN15tracked_objects10ThreadData19OnThreadTerminationEPv
    fun:_pthread_tsd_cleanup
    fun:_pthread_exit
    fun:thread_start
 }
+{
+   bug_102327_b
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN15tracked_objects10ThreadData10InitializeEv
+   fun:_ZN15tracked_objects10ThreadData23InitializeThreadContextERKSs
+}