Update co19 status on firefox and chrome.

tests/lib/lib.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 [ $unchecked ]
 mirrors/redirecting_factory_different_type_test: SkipByDesign # Tests type checks.
 
 [ $csp ]
 # Deferred loading does not work from an isolate in CSP-mode
 async/deferred/deferred_in_isolate_test: Skip # Issue 16898
@@ skipping 188 matching lines @@
 [ $compiler == dart2dart && $minified ]
 convert/json_lib_test: Fail # Issue 10961
 
 [ $compiler == dart2js && $minified ]
 mirrors/mirrors_used_get_name_test: RuntimeError
 mirrors/mirrors_used_get_name2_test: RuntimeError
 
 [ $runtime == ff ]
 # FF setTimeout can fire early: https://bugzilla.mozilla.org/show_bug.cgi?id=291386
 convert/streamed_conversion_utf8_decode_test: Pass, Slow  # Issue 12029
-convert/streamed_conversion_utf8_encode_test: Pass, Slow # Issue 12029
 mirrors/mirrors_reader_test: Timeout, Slow, RuntimeError # Issue 16589
 
+[ $runtime == chrome || $runtime == ff]
+convert/streamed_conversion_utf8_encode_test: Pass, Slow, Timeout # Issue 12029
+async/slow_consumer2_test: Pass, Timeout # Please triage this issue.
+
 [ $compiler == dart2js ]
 typed_data/typed_data_hierarchy_int64_test: RuntimeError # Issue 10275
 typed_data/int32x4_bigint_test: RuntimeError # Issue 1533
 typed_data/int64_list_load_store_test: RuntimeError # Issue 10275
 
 [ $runtime == opera ]
 async/multiple_timer_test: Pass, Fail # Probably issue 14734
 
 [ $runtime == opera && $system == windows]
 # TODO(efortuna): Investigate.
@@ skipping 89 matching lines @@
 profiler/metrics_num_test: Skip # Because of a int / double type test.
 
 [ $arch == simarm64 ]
 convert/utf85_test: Skip # Pass, Slow Issue 20111.
 
 [ $mode == debug && $arch == ia32 && $system == windows ]
 convert/streamed_conversion_json_utf8_decode_test: Skip  # Verification OOM.
 
 [ $mode == debug && $arch != ia32 && $arch != x64 && $arch != simarm ]
 convert/streamed_conversion_json_utf8_decode_test: Skip  # Verification not yet implemented.