re-enable browser_480148.js on OS X

browser/components/sessionstore/test/browser/Makefile.in

@@ -98,6 +98,7 @@ _BROWSER_TEST_FILES = \
 	browser_476161.js \
 	browser_476161_sample.html \
 	browser_477657.js \
+	browser_480148.js \
 	browser_480893.js \
 	browser_483330.js \
 	browser_485482.js \
@@ -115,9 +116,5 @@ _BROWSER_TEST_FILES = \
 	browser_528776.js \
 	$(NULL)
 
-ifneq ($(MOZ_WIDGET_TOOLKIT),cocoa)
-_BROWSER_TEST_FILES += browser_480148.js
-endif
-
 libs:: $(_BROWSER_TEST_FILES)
 	$(INSTALL) $(foreach f,$^,"$f") $(DEPTH)/_tests/testing/mochitest/browser/$(relativesrcdir)