WebRTC: Add Libfuzzer commit and trybot.

masters/master.tryserver.webrtc/slaves.cfg

 # Copyright (c) 2012 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.
 
 slaves = [
   # Linux.
   {
     'master': 'WebRTCTryServer',
     'os': 'linux',
     'version': 'precise',
     'bits': '64',
     'builder': [
       'android_clang_dbg',
       'android_compile_dbg',
       'android_compile_rel',
       'android_compile_arm64_dbg',
       'android_compile_arm64_rel',
       'android_compile_x86_dbg',
       'android_compile_x64_dbg',
       'android_gn_dbg',
       'android_gn_rel',
       'linux_compile_dbg',
       'linux_compile_rel',
       'linux_dbg',
       'linux_rel',
       'linux_gn_dbg',
       'linux_gn_rel',
+      'linux_libfuzzer_rel',
       'linux_asan',
       'linux_memcheck',
       'linux_msan',
       'linux_swarming',
       'linux_tsan2',
       'linux_ubsan',
       'linux_ubsan_vptr',
       'presubmit',
     ],
     'hostname': 'slave%d-c4' % i,
@@ skipping 133 matching lines @@
     'master': 'WebRTCTryServer',
     'os': 'win',
     'version': 'win7',
     'bits': '64',
     'builder': [
       'win_baremetal',
     ],
     'hostname': 'build23-a4',
   }
 ]