Fix FF tests

pkg/dev_compiler/test/browser/language_tests.js

Index: pkg/dev_compiler/test/browser/language_tests.js
diff --git a/pkg/dev_compiler/test/browser/language_tests.js b/pkg/dev_compiler/test/browser/language_tests.js
index 694ee0147471db866b365faa3cc0440b1e9b1578..748404a6da05137cf9a4eb31f7b8ca958b4bd5be 100644
--- a/pkg/dev_compiler/test/browser/language_tests.js
+++ b/pkg/dev_compiler/test/browser/language_tests.js
@@ -200,6 +200,7 @@ define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require'],
       'many_generic_instanceof_test': fail,
       'map_literal10_test': fail,
       'map_literal7_test': fail,
+      'memory_swap_test': is.firefox() ? skip_timeout : pass,
       'method_invocation_test': fail,
       'mint_arithmetic_test': fail,
       'mixin_forwarding_constructor3_test': fail,
@@ -227,7 +228,7 @@ define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require'],
       'regress_16640_test': fail,
       'regress_18535_test': fail,
       'regress_22666_test': fail,
-      'regress_22777_test': fail,
+      'regress_22777_test': is.firefox() ? 'skip' : fail, // flake on ff
       'setter_no_getter_test_01_multi': fail,
       'stack_overflow_stacktrace_test': fail,
       'stack_overflow_test': fail,