Ensures that audio tasks cannot run after AudioManager is deleted.

content/public/browser/content_browser_client.cc

Index: content/public/browser/content_browser_client.cc
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index f9f587be5b12f72a55688107add330dbba06c116..4fa3b21cc91d78b28c765362d7df71c194ae8a94 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -13,6 +13,7 @@
 #include "content/public/browser/navigation_ui_data.h"
 #include "content/public/browser/vpn_service_proxy.h"
 #include "content/public/common/sandbox_type.h"
+#include "media/audio/audio_manager.h"
 #include "media/base/cdm_factory.h"
 #include "media/media_features.h"
 #include "storage/browser/quota/quota_manager.h"
@@ -114,7 +115,9 @@ bool ContentBrowserClient::ShouldSwapBrowsingInstancesForNavigation(
   return false;
 }
 
-media::ScopedAudioManagerPtr ContentBrowserClient::CreateAudioManager(
+std::unique_ptr<media::AudioManager> ContentBrowserClient::CreateAudioManager(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
     media::AudioLogFactory* audio_log_factory) {
   return nullptr;
 }