Bug 879316 - Clean up CSP logging code. r=imelven
Bug 882817 - Fix QI implementation of HTMLTrackElement. r=bz

In certain situations we were failing debug builds due to an assertion
that HTMLTrackElement was not a nsIDOMNode or nsIDOMWindow when calling
NS_CheckContentLoadPolicy in HTMLTrackElement::LoadResource()

This patch fixes the QI of the HTMLTrackElement so that it can be queried
to an nsIDOMNode correctly.