Bug 1044737 - 1/3: don't use Date in nsINetworkStatsCallback::networkStatsAvailable. r=vchang
Bug 1044737 - 2/3: remove unused bits related to 'getNetworkInterfaceStats'. r=bholley, r=vchang
Bug 1044737 - 3/3: fix NetworkStatsService::networkStatsAvailable and test cases. r=vchang