imgIDecoderObserver_MOZILLA_1_8_BRANCH Interface

 called at the same time that nsIRequestObserver::onStartRequest would be
 (used only for observers of imgIRequest objects, which are nsIRequests,
 not imgIDecoder objects)

 Unlike nsIRequestObserver::onStartRequest, this can be called
 synchronously.

void onStartRequest(in imgIRequest aRequest)

 called at the same time that nsIRequestObserver::onStopRequest would be
 (used only for observers of imgIRequest objects, which are nsIRequests,
 not imgIDecoder objects)

 Unlike nsIRequestObserver::onStartRequest, this can be called
 synchronously.

void onStopRequest(in imgIRequest aRequest, in boolean aIsLastPart)