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 6387bb776c295628ab0ea2c39c07ee13ac56fd62..f51d9a1f370e832da6e897647aee9362741f063e 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -15,6 +15,7 @@
 #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"
@@ -116,7 +117,7 @@ bool ContentBrowserClient::ShouldSwapBrowsingInstancesForNavigation(
   return false;
 }
 
-media::ScopedAudioManagerPtr ContentBrowserClient::CreateAudioManager(
+std::unique_ptr<media::AudioManager> ContentBrowserClient::CreateAudioManager(
     media::AudioLogFactory* audio_log_factory) {
   return nullptr;
 }