Removed the invalid AudioOutputController suppression.

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 # running overnight and removing outdated bugs/suppressions.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 4674 matching lines @@
    fun:_ZN8notifier5Login15StartConnectionEv
    fun:_ZN13sync_notifier20InvalidationNotifier17UpdateCredentialsERKSsS2_
 }
 {
    bug_118890_b
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN13sync_notifier12_GLOBAL__N_124InvalidationNotifierTest5SetUpEv
 }
 {
-   bug_120146
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN4base8internal20PostTaskAndReplyImpl16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEESA_
-   fun:_ZN4base10TaskRunner16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEES9_
-   fun:_ZN5media21AudioOutputController5CloseERKN4base8CallbackIFvvEEE
-   fun:_ZN17AudioRendererHost20CloseAndDeleteStreamEPNS_10AudioEntryE
-   fun:_ZN17AudioRendererHost13DeleteEntriesEv
-   fun:_ZN17AudioRendererHost16OnChannelClosingEv
-   fun:_ZN3IPC12ChannelProxy7Context15OnChannelClosedEv
-}
-{
    bug_121729
    Memcheck:Leak
    fun:malloc
    fun:_ZN3WTF10fastMallocE*
    ...
    fun:_ZN7WebCoreL12parseUASheetERKN3WTF6StringE
    fun:_ZN7WebCoreL12parseUASheetEPKcj
    fun:_ZN7WebCoreL19loadViewSourceStyleEv
    ...
    fun:_ZN7WebCore7Element16styleForRendererEv
@@ skipping 1760 matching lines @@
    fun:sqlite3VdbeExec
    fun:sqlite3Step
    fun:sqlite3_step
    fun:_ZN7WebCore15SQLiteStatement4stepEv
    fun:_ZN7WebCore15SQLiteStatement14executeCommandEv
    fun:_ZN7WebCore14SQLiteDatabase14executeCommandERKN3WTF6StringE
    fun:_ZN7WebCore17SQLiteTransaction6commitEv
    fun:_ZN7WebCore14SQLTransaction19postflightAndCommitEv
    fun:_ZN7WebCore14SQLTransaction13runStatementsEv
 }