User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0 Build ID: 20150108202552 Steps to reproduce: Enter a 1st uri in address bar. Before it is loaded, enter a new uri. Note: The 1st uri need to be slow enough to fetch (or erroneous such as inexistant domain name) in order to produce this bug. Actual results: If the 2nd uri's page is loaded/displayed fast, then the 1st uri's page will be loaded/displayed (or 1st uri error if any) after. Expected results: The 1st uri load operation should be canceled when the 2nd one is started so that when entering a new uri, the previous one can't be displayed after the latest.