Fix leak in BroadcastNotifications() if the delegate is closing

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 # running overnight and removing outdated bugs/suppressions.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 3695 matching lines @@
    fun:_ZN17VisitedLinkMaster23RebuildTableFromHistoryEv
    fun:_ZN17VisitedLinkMaster15InitFromScratchEb
    fun:_ZN17VisitedLinkMaster4InitEv
    fun:_ZN11ProfileImpl20GetVisitedLinkMasterEv
    fun:_ZN24VisitedLinkEventListener7ObserveEiRK18NotificationSourceRK19NotificationDetails
    fun:_ZN19NotificationService6NotifyEiRK18NotificationSourceRK19NotificationDetails
    fun:_ZN24BrowserRenderProcessHost17OnProcessLaunchedEv
    fun:_ZN20ChildProcessLauncher7Context6NotifyEbi
 }
 {
-   bug_86483b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN7history14HistoryBackend12AddPageVisitERK4GURLN4base4Time*
-   fun:_ZN7history14HistoryBackend7AddPageE13scoped_refptrINS_18HistoryAddPageArgsEE
-}
-{
-   bug_86483c
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN7history14HistoryBackend12SetPageTitleE*
-}
-{
    bug_87094a
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN4base4Bind*TaskClosureAdapter*InvokerStorage*
    fun:_ZN11MessageLoop8PostTaskERKN15tracked_objects8LocationEP4Task
    fun:_ZN3net10FileStream12AsyncContext23OnBackgroundIOCompletedEi
    fun:_Z16DispatchToMethodIN3net10FileStream12AsyncContextEMS2_FviEiEvPT_T0_RK6Tuple1IT1_E
    fun:_ZN12CallbackImplIN3net10FileStream12AsyncContextEMS2_FviE6Tuple1IiEE13RunWithParamsERKS6_
    fun:_ZN14CallbackRunnerI6Tuple1IiEE3RunIiEEvRKT_
    fun:_ZN3net12_GLOBAL__N_112ReadFileTaskEiPciP14CallbackRunnerI6Tuple1IiEE
@@ skipping 1511 matching lines @@
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }