Remove unnecessary casts in AudioManagerDeleter on Mac.

media/audio/audio_manager.cc

Index: media/audio/audio_manager.cc
diff --git a/media/audio/audio_manager.cc b/media/audio/audio_manager.cc
index 2ff852b78cff3d9c67ff3d6710c2402eb088ef61..47f3ec842b86aa560026f748e851754c6781a894 100644
--- a/media/audio/audio_manager.cc
+++ b/media/audio/audio_manager.cc
@@ -6,6 +6,8 @@
 
 #include <stdint.h>
 
+#include <utility>

[Max Morin, 2017/02/16 15:10:51]

Linter wanted it for move.

+
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ -287,9 +289,7 @@ void AudioManagerDeleter::operator()(const AudioManager* instance) const {
   // uses a state that is destroyed in ~BrowserMainLoop().
   // See http://crbug.com/623703 for more details.
   DCHECK(instance->GetTaskRunner()->BelongsToCurrentThread());
-  AudioManagerMac* mac_instance =
-      static_cast<AudioManagerMac*>(const_cast<AudioManager*>(instance));
-  delete mac_instance;
+  delete instance;
 #else
   // AudioManager must be destroyed on the audio thread.
   if (!instance->GetTaskRunner()->DeleteSoon(FROM_HERE, instance)) {