Remove obsolete valgrind suppression

leak was fixed in r213560

BUG=175815
NOTRY=true

Review URL: https://codereview.chromium.org/383333002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282724 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/memcheck/suppressions.txt

@@ -4507,16 +4507,6 @@
    fun:_ZN20OneClickSigninHelper14DidStopLoadingEPN7content14RenderViewHostE
    fun:_ZN*OneClickSigninHelperTest*
 }
-{
-   bug_175815
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN4base5Value18CreateIntegerValueEi
-   fun:_ZNK4base16FundamentalValue8DeepCopyEv
-   fun:_ZN4base8internal12_GLOBAL__N_125DictionaryHiddenRootValue26RemoveWithoutPathExpansionERKSsPPNS_5ValueE
-   fun:_ZN4base15DictionaryValue6RemoveERKSsPPNS_5ValueE
-   fun:_ZN32PluginFinderTest_JsonSyntax_Test8TestBodyEv
-}
 {
    bug_175823
    Memcheck:Leak