Bug 1061112 - test_app_rep.js fails when "browser.safebrowsing.downloads.enabled" is false or not set. r=gcp,a=test-only

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extra : transplant_source : %BE%D5%E7J6%B9E%84f%17%08B%0A%2Ck%8F%2BCS3
Bug 1061112 - test_app_rep_windows.js needs some preference variables to be passed on comm-central. r=mmc,a=test-only

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extra : transplant_source : P%E9%D1q%8E%E7.%99%2C%F3%DD%F6%26%A2%03%8E%D5%24F%8F