Bug 829360 - Keep non-browser windows from extending the lifetime of the private session. r=bz a=bajaj

--HG--
extra : transplant_source : %12%CB%E5%18%7D%C9%E3%DD%C3%C7%DDy%8D%8F%26d%DD%A6%0A%5E
Additional logging for Bug 835197 - Intermittent test_0201_app_launch_apply_update.js, test_0202_app_launch_apply_update_dirlocked.js, test_0203_app_launch_apply_update.js [Exception... 'Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIFile.copyTo]'. r=bbondy, a=test-only
Bug 762032 - Intermittent test_0201_app_launch_apply_update_svc.js | WindowsError: [Error 13] The process cannot access the file because it is being used by another process: '...\ExecutableDir.tmp\bin\uninstall\helper.exe'. r=bbondy, a=test-only
Bug 767968 - Intermittent test_0201_app_launch_apply_update.js, test_0203_app_launch_apply_update.js | WindowsError: [Error 13] The process cannot access the file because it is being used by another process: '...\maintenanceservice_installer.exe'. r=bbondy, a=test-only