upload_manager_test can run only on chrome

package.json

@@ -120,7 +120,7 @@
         "c9.ide.theme.flat": "#81dadeee55",
         "c9.ide.threewaymerge": "#229382aa0b",
         "c9.ide.undo": "#b028bcb4d5",
-        "c9.ide.upload": "#1ebe8411cf",
+        "c9.ide.upload": "#e4351f5a2b",
         "c9.ide.welcome": "#5b86c44e92",
         "c9.ide.guide": "#df7c89e449"
     }