Widen a suppression rule for sync_notifier::InvalidationNotifier::UpdateCredentials().

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 # running overnight and removing outdated bugs/suppressions.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 5294 matching lines @@
    ...
    fun:_ZN3net9HostCache3SetERKNS0_3KeyEiRKNS_11AddressListEN4base9TimeTicksENS7_9TimeDeltaE
    fun:_ZN3net16HostResolverImpl11CacheResultERKNS_9HostCache3KeyEiRKNS_11AddressListEN4base9TimeDeltaE
    fun:_ZN3net16HostResolverImpl3Job16CompleteRequestsEiRKNS_11AddressListEN4base9TimeDeltaE
    fun:_ZN3net16HostResolverImpl3Job18OnProcTaskCompleteEiRKNS_11AddressListE
 }
 {
    bug_118890_a
    Memcheck:Leak
    ...
-   fun:_ZN27TestURLRequestContextGetter20GetURLRequestContextEv
    fun:_ZN8notifier18SingleLoginAttemptC1EPNS_13LoginSettingsEPNS0_8DelegateE
    fun:_ZN8notifier5Login15StartConnectionEv
    fun:_ZN13sync_notifier20InvalidationNotifier17UpdateCredentialsERKSsS2_
 }
 {
    bug_118890_b
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN13sync_notifier12_GLOBAL__N_124InvalidationNotifierTest5SetUpEv
 }
@@ skipping 521 matching lines @@
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }