Add mus_browser_tests to Mojo FYI bots

testing/buildbot/filters/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This BUILD.gn file groups together filter files for particular test suites -
 # for example filters applicable to content_browsertests are exposed as
 # the //testing/buildbot/filters:content_browsertests target.
 
 # Note that all filter files (for a given test suite) are unconditionally listed
 # together, even if some filter files are applicable only to some platforms.
 # This should help avoid unpleasant surprises when a bot config is switched in
 # testing/buildbot/chromium.fyi.json without corresponding dependency changes
 # here - see https://crbug.com/661447.
 
 # To refresh, a command similar to the one below might be run in bash:
 # $ for i in $(ls -1 testing/buildbot/filters/*.browser_tests.*filter ); \
 #   do echo "    \"//$i\","; done | sort
 
 source_set("browser_tests_filters") {
   testonly = true
 
   data = [
     "//testing/buildbot/filters/isolate-extensions.browser_tests.filter",
     "//testing/buildbot/filters/mash.browser_tests.filter",
     "//testing/buildbot/filters/mojo.fyi.browser_tests.filter",
+    "//testing/buildbot/filters/mojo.fyi.mus.browser_tests.filter",
     "//testing/buildbot/filters/site-per-process.browser_tests.filter",
   ]
 }
 
 source_set("content_browsertests_filters") {
   testonly = true
 
   data = [
     "//testing/buildbot/filters/cast-linux.content_browsertests.filter",
     "//testing/buildbot/filters/isolate-extensions.content_browsertests.filter",
     "//testing/buildbot/filters/site-per-process.content_browsertests.filter",
   ]
 }
 
 source_set("interactive_ui_tests_filters") {
   testonly = true
 
   data = [
     "//testing/buildbot/filters/site-per-process.interactive_ui_tests.filter",
   ]
 }
 
 source_set("ash_unittests_filters") {
   testonly = true
 
   data = [
     "//testing/buildbot/filters/ash_mus_unittests.filter",
   ]
 }