Fix leak of a DownloadItem in SavePackage::Init.

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 # running overnight and removing outdated bugs/suppressions.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 2674 matching lines @@
    fun:_ZN11ProfileImpl21GetProfileSyncServiceEv
    ...
    fun:_ZN7BrowserC1ENS_4TypeEP7Profile
    ...
    fun:_ZN11BrowserInit17LaunchWithProfile6LaunchEP7Profileb
    fun:_ZN11BrowserInit13LaunchBrowserERK11CommandLineP7ProfileRK8FilePathbPi
    fun:_ZN11BrowserInit18ProcessCmdLineImplERK11CommandLineRK8FilePathbP7ProfilePiPS_
    fun:_ZN11BrowserInit5StartERK11CommandLineRK8FilePathP7ProfilePi
 }
 {
-   bug_56495
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN11SavePackage4InitEv
-   fun:_ZN11TabContents8SavePageERK8FilePathS2_N11SavePackage15SavePackageTypeE
-   fun:_ZN25TestingAutomationProvider8SavePageEiRK8FilePathS2_iPb
-   fun:_Z16DispatchToMethodI25TestingAutomationProviderMS0_FviRK8FilePathS3_iPbEiS1_S1_ibEvPT_T0_RK6Tuple4IT1_T2_T3_T4_EP6Tuple1IT5_E
-   fun:_ZN3IPC16MessageWithReplyI6Tuple4Ii8FilePathS2_iE6Tuple1IRbEE8DispatchI25TestingAutomationProviderMS9_FviRKS2_SB_iPbEEEbPKNS_7MessageEPT_T0_
-   fun:_ZN25TestingAutomationProvider17OnMessageReceivedERKN3IPC7MessageE
-   fun:_ZN3IPC12ChannelProxy7Context17OnDispatchMessageERKNS_7MessageE
-   fun:_ZN3IPC11SyncChannel20ReceivedSyncMsgQueue16DispatchMessagesEv
-}
-{
    bug_56676
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN9__gnu_cxx13new_allocatorIN4base15file_util_proxy5EntryEE8allocate*
    fun:_ZNSt12_Vector_baseIN4base15file_util_proxy5EntryESaIS2_EE11_M_allocate*
    fun:_ZNSt6vectorIN4base15file_util_proxy5EntryESaIS2_EE20_M_allocate_and_copyIN9__gnu_cxx17__normal_iteratorIPKS2*
    fun:_ZNSt6vectorIN4base15file_util_proxy5EntryESaIS2_EEaSERKS4_
    fun:_ZN14MockDispatcher16DidReadDirectoryERKSt6vectorIN4base15file_util_proxy5EntryESaIS3_EEb
    fun:_ZN7fileapi19FileSystemOperation16DidReadDirectoryEN4base17PlatformFileErrorERKSt6vectorINS1_15file_util_proxy5EntryESaIS5_EE
    fun:_Z16DispatchToMethodIN7fileapi19FileSystemOperationEMS1_FvN4base17PlatformFileErrorERKSt6vectorINS2_15file_util_proxy5EntryESaIS6_EEES3_SA_EvPT_T0_RK6Tuple2IT1_T2_E
@@ skipping 17 matching lines @@
    fun:_ZN8chromeos13OnlineAttempt14TryClientLoginEv
    fun:_ZN8chromeos13OnlineAttempt20OnClientLoginFailureERK22GoogleServiceAuthError
    fun:_ZN18GaiaAuthenticator220OnClientLoginFetchedERKSsRK16URLRequestStatusi
    fun:_ZN18GaiaAuthenticator218OnURLFetchCompleteEPK10URLFetcherRK4GURLRK16URLRequestStatusiRKSt6vectorISsSaISsEERKSs
    fun:_ZN8chromeos18GotCanceledFetcher5StartEv
    fun:_ZN18GaiaAuthenticator216StartClientLoginERKSsS1_PKcS1_S1_
    fun:_ZN8chromeos13OnlineAttempt14TryClientLoginEv
    fun:_ZN8chromeos13OnlineAttempt8InitiateEP7Profile
    fun:_ZN8chromeos17OnlineAttemptTest13RunCancelTestEPNS_13OnlineAttemptEP7Profile
 }