Remove a valgrind suppression which isn't being used....

tools/valgrind/memcheck/suppressions.txt

 # There are three 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 # running overnight and removing outdated bugs/suppressions.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 923 matching lines @@
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN3net26DefaultClientSocketFactory21CreateTCPClientSocketERKNS_11AddressListE
    fun:_ZN3net13TCPConnectJob12DoTCPConnectEv
    fun:_ZN3net13TCPConnectJob6DoLoopEi
    fun:_ZN3net13TCPConnectJob12OnIOCompleteEi
    ...
    fun:_ZN3net16HostResolverImpl3Job16OnLookupCompleteEv
 }
 {
-   bug_22559_1
-   Memcheck:Value4
-   ...
-   fun:_ZN4base9vsnprintfEPcjPKcS0_
-   fun:_Z10vsnprintfTPcjPKcS_
-   fun:_Z14StringAppendVTISsEvPT_PKNS0_10value_typeEPc
-   fun:_Z13StringAppendVPSsPKcPc
-   fun:_Z13StringAppendFPSsPKcz
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter23WriteWithOptionalEscapeEPK5ValuebbPSs
-   fun:_ZN10JSONWriter5WriteEPK5ValuebPSs
-   fun:_ZN25JSONStringValueSerializer9SerializeERK5Value
-   fun:_ZN11PrefService13SerializeDataEPSs
-   fun:_ZN11PrefService19SavePersistentPrefsEv
-   fun:_ZN16browser_shutdown8ShutdownEv
-}
-{
-   bug_22559_2
-   Memcheck:Cond
-   ...
-   fun:_ZN4base9vsnprintfEPcjPKcS0_
-   fun:_Z10vsnprintfTPcjPKcS_
-   fun:_Z14StringAppendVTISsEvPT_PKNS0_10value_typeEPc
-   fun:_Z13StringAppendVPSsPKcPc
-   fun:_Z13StringAppendFPSsPKcz
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter15BuildJSONStringEPK5Valueib
-   fun:_ZN10JSONWriter23WriteWithOptionalEscapeEPK5ValuebbPSs
-   fun:_ZN10JSONWriter5WriteEPK5ValuebPSs
-   fun:_ZN25JSONStringValueSerializer9SerializeERK5Value
-   fun:_ZN11PrefService13SerializeDataEPSs
-   fun:_ZN11PrefService19SavePersistentPrefsEv
-   fun:_ZN16browser_shutdown8ShutdownEv
-}
-{
    bug_22702
    Memcheck:Cond
    fun:_ZN7WebCore23V8AbstractEventListener18invokeEventHandlerEN2v86HandleINS1_7ContextEEEPNS_5EventENS2_INS1_5ValueEEEb
    fun:_ZN7WebCore23V8AbstractEventListener11handleEventEPNS_5EventEb
 }
 {
    bug_22923
    Memcheck:Leak
    fun:_Znw*
    ...
@@ skipping 194 matching lines @@
    fun:_ZN3WTF31dispatchFunctionsFromMainThreadEv
    fun:_Z18DispatchToFunctionIPFvvEEvT_RK6Tuple0
    fun:_ZN16RunnableFunctionIPFvvE6Tuple0E3RunEv
    fun:_ZN11MessageLoop7RunTaskEP4Task
    fun:_ZN11MessageLoop21DeferOrRunPendingTaskERKNS_11PendingTaskE
    fun:_ZN11MessageLoop6DoWorkEv
    fun:_ZN4base18MessagePumpDefault3RunEPNS_11MessagePump8DelegateE
    fun:_ZN11MessageLoop11RunInternalEv
    fun:_ZN11MessageLoop10RunHandlerEv
 }