Bug 1403935: Enable OMTP by default on windows only. r=dvander

MozReview-Commit-ID: HcizKS5zv9v

modules/libpref/init/all.js

@@ -5914,6 +5914,10 @@ pref("toolkit.crashreporter.include_context_heap", true);
 // Open noopener links in a new process
 pref("dom.noopener.newprocess.enabled", true);
 
+#ifdef XP_WIN
+pref("layers.omtp.enabled", true);
+#else
 pref("layers.omtp.enabled", false);
+#endif
 pref("layers.omtp.release-capture-on-main-thread", true);
 pref("layers.omtp.force-sync", false);