Suppress leak in AudioOutputController.

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 # running overnight and removing outdated bugs/suppressions.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 5749 matching lines @@
    fun:_ZN14ProfileManager17GetDefaultProfileERK8FilePath
    fun:_ZN14ProfileManager17GetDefaultProfileEv
    fun:_ZN22ChromeLauncherDelegateC1EP7ProfilePN3ash13LauncherModelE
    fun:_ZN19ChromeShellDelegate22CreateLauncherDelegateEPN3ash13LauncherModelE
    fun:_ZN3ash8LauncherC1EPN4aura6WindowE
    fun:_ZN3ash5Shell14CreateLauncherEv
    fun:_ZN3ash5Shell4InitEv
    fun:_ZN3ash5Shell14CreateInstanceEPNS_13ShellDelegateE
    fun:_ZN30ChromeBrowserMainExtraPartsAsh14PreProfileInitEv
 }
+{
+   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
+}
 
 #-----------------------------------------------------------------------
 # 4. These only occur on our Google workstations
 
 {
    bug_todo_getdelim
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    ...
    fun:call_init
    fun:_dl_init
 }
 {
    bug_todo_getdelim2
    Memcheck:Leak
    fun:malloc
    fun:getdelim
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
    obj:/lib/libselinux.so.1
 }
 {
    bug_todo_grep
    Memcheck:Leak
    fun:malloc
    obj:/bin/grep
    obj:/bin/grep
 }