[MemSheriff] Retire unused suppression.

Already marked as retired on bug, suppressions query has no results for
this either.

BUG=258466
R=thestig@chromium.org
TBR=thestig@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/309533015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274338 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/memcheck/suppressions.txt

@@ -5446,20 +5446,6 @@
    fun:_ZN7content12_GLOBAL__N_134ClearQuotaManagedOriginsOnIOThreadERK13scoped_refptrIN5quota12QuotaManagerEERKSt3setI4GURLSt4lessIS8_ESaIS8_EENS2_11StorageTypeE
    fun:_ZN7content12_GLOBAL__N_121ClearOriginOnIOThreadEjRK4GURLRK13scoped_refptrIN3net23URLRequestContextGetterEERKS4_IN5quota12QuotaManagerEE
 }
-{
-   bug_258466
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN22ChromeBrowserMainParts25PreMainMessageLoopRunImplEv
-   fun:_ZN22ChromeBrowserMainParts21PreMainMessageLoopRunEv
-   fun:_ZN7content15BrowserMainLoop13CreateThreadsEv
-   fun:_ZN7content21BrowserMainRunnerImpl10InitializeERKNS_18MainFunctionParamsE
-   fun:_ZN7content11BrowserMainERKNS_18MainFunctionParamsE
-   fun:_ZN7content23RunNamedProcessTypeMainERKSsRKNS_18MainFunctionParamsEPNS_19ContentMainDelegateE
-   fun:_ZN7content21ContentMainRunnerImpl3RunEv
-   fun:_ZN7content11ContentMainEiPPKcPNS_19ContentMainDelegateE
-   fun:ChromeMain
-}
 {
    bug_258132a
    Memcheck:Leak