Bug 996055 - Prevent url.hostname from clearing the hostname. r=mcmanus
Bug 997367 - fix crash at CrossProcessCompositorParent::GetCompositionManager. r=roc
Bug 991116 - Intermittent test_ping_aboutnetworking.js. r=mcmanus
Use nsMainThreadPtrHandle<NetDashboardCallback> for JS objects.
Remove pointles code that clears the JS callback.
Fix test using out of scope variable.