Backed out changeset af66c0b94881 for landing with the wrong bug number in the commit message.

dom/audiochannel/AudioChannelService.cpp

@@ -634,12 +634,7 @@ AudioChannelService::IsWindowActive(nsPIDOMWindowOuter* aWindow)
   if (!window) {
     return false;
   }
-
-  AudioChannelWindow* winData = GetWindowData(window->WindowID());
-  if (!winData) {
-    return false;
-  }
-
+  AudioChannelWindow* winData = GetOrCreateWindowData(window);
   return !winData->mAudibleAgents.IsEmpty();
 }