Mac: Fix leak in tabpose.

tools/valgrind/memcheck/suppressions_mac.txt

 # There are three kinds of suppressions in this file:
 # 1. Third party stuff we have no control over.
 #
 # 2. Intentional unit test errors, 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.
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1482 matching lines @@
    Memcheck:Cond
    fun:gleUpdateViewScissorData
    ...
    fun:cgl_set_surface
    fun:ogl_attach_surface
    fun:ogl_render_fade_transition
    fun:ogl_render_layer_
    fun:ogl_render_layers
 }
 {
-   bug_51786
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN7tabpose7TileSet5BuildEP13TabStripModel
-   fun:-[TabposeWindow setUpLayers:slomo:]
-   fun:-[TabposeWindow initForWindow:rect:slomo:tabStripModel:]
-   fun:_ZN31TabposeWindowTest_TestShow_Test8TestBodyEv
-}
-{
    bug_52364_a
    Memcheck:Value4
    fun:_ZNK10CMMConvLut7ConvertER10CMMMinBitsP14CMMRuntimeInfomm
    fun:_Z16CMMProcessBitmapP15CMMBitmapParams
    fun:DoMatchBitmap
    fun:CWMatchBitmap
    fun:ConvertImageGeneric
    fun:CMSColorWorldConvertData
    fun:CMSTransformConvertData
    fun:CGCMSInterfaceTransformConvertData
@@ skipping 20 matching lines @@
    fun:_ZN16ChildProcessHost13CreateChannelEv
    fun:_ZN18UtilityProcessHost12StartProcessERK8FilePath
    fun:_ZN18UtilityProcessHost22StartExtensionUnpackerERK8FilePath
    fun:_ZN14RunnableMethodI26SandboxedExtensionUnpackerMS0_FvRK8FilePathE6Tuple1IS1_EE3RunEv
    fun:_ZN11MessageLoop7RunTaskEP4Task
    fun:_ZN11MessageLoop21DeferOrRunPendingTaskERKNS_11PendingTaskE
    fun:_ZN11MessageLoop6DoWorkEv
    fun:_ZN4base19MessagePumpLibevent3RunEPNS_11MessagePump8DelegateE
    fun:_ZN11MessageLoop11RunInternalEv
 }