Allow content embedders to create AudioManager.

chromecast/browser/cast_content_browser_client.cc

Index: chromecast/browser/cast_content_browser_client.cc
diff --git a/chromecast/browser/cast_content_browser_client.cc b/chromecast/browser/cast_content_browser_client.cc
index d2b924783f56d7e9655902946cfb28057cf18e59..fd05603197ef1fa5618e32b778af800225696223 100644
--- a/chromecast/browser/cast_content_browser_client.cc
+++ b/chromecast/browser/cast_content_browser_client.cc
@@ -32,6 +32,7 @@
 #include "chromecast/browser/service/cast_service_simple.h"
 #include "chromecast/browser/url_request_context_factory.h"
 #include "chromecast/common/global_descriptors.h"
+#include "chromecast/media/audio/cast_audio_manager.h"
 #include "chromecast/media/cma/backend/media_pipeline_backend_manager.h"
 #include "chromecast/public/media/media_pipeline_backend.h"
 #include "components/crash/content/app/breakpad_linux.h"
@@ -418,6 +419,13 @@ void CastContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
 }
 
 #else
+::media::AudioManager* CastContentBrowserClient::CreateAudioManager(
+    ::media::AudioLogFactory* audio_log_factory) {
+  // The caller owns the returned instance.
+  return new media::CastAudioManager(GetMediaTaskRunner(), GetMediaTaskRunner(),
+                                     audio_log_factory,
+                                     media_pipeline_backend_manager());
+}
 
 std::unique_ptr<::media::CdmFactory>
 CastContentBrowserClient::CreateCdmFactory() {