Suppress use-after-free in base::Thread::ThreadMain()

tools/valgrind/memcheck/suppressions.txt

 # There are four kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or 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 (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 5780 matching lines @@
 }
 {
    bug_128145b
    Memcheck:Leak
    ...
    fun:_ZL19BuildWebDataServiceP7Profile
    fun:_ZN36RefcountedProfileKeyedServiceFactory20GetServiceForProfileEP7Profileb
    fun:_ZN36RefcountedProfileKeyedServiceFactory23SetTestingFactoryAndUseEP7ProfilePF13scoped_refptrI29RefcountedProfileKeyedServiceES1_E
    fun:_ZN14TestingProfile20CreateWebDataServiceEv
 }
+{
+   bug_127931
+   Memcheck:Unaddressable
+   fun:_ZN4base6Thread10ThreadMainEv
+   fun:_ZN4base12_GLOBAL__N_110ThreadFuncEPv
+}
 
 #-----------------------------------------------------------------------
 # 4. These only occur on our Google workstations
 
 {
    bug_todo_getdelim
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    ...
    fun:call_init
    fun:_dl_init
 }
 {
    bug_todo_getdelim2
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }