Motown: Fix audio server regression
Caused by https://codereview.chromium.org/2015643002/

R=kulakowski@chromium.org

Review URL: https://codereview.chromium.org/2026963002 .

services/media/audio/audio_server_app.cc

diff --git a/services/media/audio/audio_server_app.cc b/services/media/audio/audio_server_app.cc
index 2f25fdd..ceb407b 100644
--- a/services/media/audio/audio_server_app.cc
+++ b/services/media/audio/audio_server_app.cc
@@ -17,7 +17,9 @@
 
 AudioServerApp::~AudioServerApp() {}
 
-void AudioServerApp::OnInitialize() {}
+void AudioServerApp::OnInitialize() {
+  server_impl_.Initialize();
+}
 
 bool AudioServerApp::OnAcceptConnection(
     ServiceProviderImpl* service_provider_impl) {