Bug 1199678 - recognize MS Edge in MigrationUtils.jsm for default browser detection, r=Dolske

MozReview-Commit-ID: Bmuyv59fRAv

--HG--
extra : rebase_source : 0869e916cf5adda158f417d0a50160a37bc8ff40

browser/components/migration/MigrationUtils.jsm

@@ -529,6 +529,7 @@ this.MigrationUtils = Object.freeze({
     // Canary uses the same description as Chrome so we can't distinguish them.
     const APP_DESC_TO_KEY = {
       "Internet Explorer":                 "ie",
+      "Microsoft Edge":                    "edge",
       "Safari":                            "safari",
       "Firefox":                           "firefox",
       "Google Chrome":                     "chrome",  // Windows, Linux