[MediaSession,Android] Request audio focus if needed when resuming playback from UI

content/browser/media/android/media_session.cc

Index: content/browser/media/android/media_session.cc
diff --git a/content/browser/media/android/media_session.cc b/content/browser/media/android/media_session.cc
index b52e67a8c697127a2fa151afa85ce62bd685c36a..a8b64efec4c97877fd06bbb644fb14dc63781919 100644
--- a/content/browser/media/android/media_session.cc
+++ b/content/browser/media/android/media_session.cc
@@ -128,6 +128,14 @@ void MediaSession::OnResume(JNIEnv* env, jobject obj) {
 void MediaSession::Resume() {
   DCHECK(IsSuspended());
 
+  // Request audio focus again in case we lost it because another app started
+  // playing while the playback was paused.
+  audio_focus_state_ = RequestSystemAudioFocus(audio_focus_type_)
+                           ? State::ACTIVE
+                           : State::INACTIVE;
+  if (audio_focus_state_ != State::ACTIVE)
+    return;
+
   OnResumeInternal(SuspendType::UI);
 }