Attempt at adding an observer before XRE_main runs

Main.cpp

// in main.cpp

#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsServiceManagerUtils.h"


class nsBlahObserver final : public nsIObserver
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIOBSERVER

  nsBlahObserver() {}

protected:
  ~nsBlahObserver() {}
};

NS_IMPL_ISUPPORTS(nsBlahObserver, nsIObserver)

NS_IMETHODIMP
nsBlahObserver::Observe(nsISupports* aSubject, const char* aTopic,
                            const char16_t* aData)
{
  printf("!!!!!!!!!!!%s\n", aTopic);

  return NS_OK;
}

// in main():
  nsCOMPtr<nsIObserverService> os(do_GetService("@mozilla.org/observer-service;1"));
  if (os) {
  nsBlahObserver* observer = new nsBlahObserver();;
  os->AddObserver(observer, "abc", false);

  }