Make Valgrind memcheck work in swarming.

webrtc/build/mb_config.pyl

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # FOR DETAILS ON THIS FILE SEE THE MAIN COPY IN //tools/mb/mb_config.pyl.
 # This is configuration for standalone WebRTC bots. It is used to keep the bot
@@ skipping 107 matching lines @@
       # Linux
       'linux_compile_dbg': 'debug_bot_x64',
       'linux_compile_rel': 'release_bot_x64',
       'linux_dbg': 'debug_bot_x64',
       'linux_rel': 'release_bot_x64',
       'linux32_dbg': 'debug_bot_x86',
       'linux32_rel': 'release_bot_x86',
       'linux_arm': 'release_bot_arm',
       'linux_asan': 'asan_lsan_clang_release_bot_x64',
       'linux_memcheck': 'release_bot_x64',
+      'linux_memcheck_swarming': 'memcheck_release_bot_x64',
       'linux_msan': 'msan_clang_release_bot_x64',
       'linux_tsan2': 'tsan_clang_release_bot_x64',
       'linux_ubsan': 'ubsan_clang_release_bot_x64',
       'linux_ubsan_vptr': 'ubsan_vptr_clang_release_bot_x64',
       'linux_baremetal': 'release_bot_x64',
 
       # Android
       'android_compile_dbg': 'android_debug_static_bot_arm',
       'android_compile_rel': 'android_release_bot_arm',
       'android_compile_arm64_dbg': 'android_debug_static_bot_arm64',
@@ skipping 300 matching lines @@
 
     'x64': {
       'gn_args': 'target_cpu="x64"',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
     },
   },
 }