Remove an unneeded Hunspell suppression and remove reference to an obsolete Hunspell test.

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 # running overnight and removing outdated bugs/suppressions.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 5719 matching lines @@
    Memcheck:Unaddressable
    ...
    fun:_ZN6WebKit31WorkerFileSystemCallbacksBridge4stopEv
    fun:_ZN6WebKit31WorkerFileSystemContextObserver10notifyStopEv
    fun:_ZN7WebCore13WorkerContext21notifyObserversOfStopEv
    fun:_ZN7WebCore29WorkerThreadShutdownStartTask11performTaskEPNS_22ScriptExecutionContextE
    fun:_ZN7WebCore13WorkerRunLoop4Task11performTaskERKS0_PNS_22ScriptExecutionContextE
    fun:_ZN7WebCore13WorkerRunLoop15runCleanupTasksEPNS_13WorkerContextE
 }
 {
-   bug_112857
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN18SpellCheckProvider19RequestTextCheckingERKN6WebKit9WebStringEiPNS0_25WebTextCheckingCompletionE
-   fun:_ZN12_GLOBAL__N_141SpellCheckProviderTest_UsingHunspell_Test8TestBodyEv
-}
-{
    bug_113076
    Memcheck:Uninitialized
    fun:_ZL19ConvertYUVToRGB32_ChhhPh
    fun:LinearScaleYUVToRGB32RowWithRange_C
    fun:_ZN5media23ScaleYUVToRGB32WithRectEPKhS1_S1_Phiiiiiiiiiii
    fun:_ZN8remoting29ConvertAndScaleYUVToRGB32RectEPKhS1_S1_iiRK7SkTSizeIiERK7SkIRectPhiS5_S8_S8_
    fun:_ZN8remoting14YuvToRgbTester7RunTestE7SkTSizeIiERK7SkIRect
 }
 {
    bug_114000
@@ skipping 171 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
 }