Enable LogDog on chromium.gatekeeper.

scripts/slave/logdog-params.pyl

 # Copyright (c) 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 is a Python literal file describing LogDog builder configuration for
 # sepcific Chromium Infrastructure BuildBot masters.
 #
 # Master names do not include the "master." prefix.
 #
 # The mapping looks like:
@@ skipping 55 matching lines @@
     'chromium.win': {},
 
     'chromium.fyi': {},
     'chromium.gpu': {},
     'chromium.perf': {},
     'chromium.perf.fyi': {},
     'chromium.webrtc': {},
     'chromium.webrtc.fyi': {},
     'chromium.webkit': {},
 
+    'chromium.gatekeeper': {},
+
     # Blink
     'tryserver.blink': {},
 
     # V8
     'client.v8': {},
     'client.v8.branches': {},
     'client.v8.fyi': {},
     'client.v8.ports': {},
     'tryserver.v8': {},
 
     # NaCl / WASM
     'client.nacl': {},
     'client.nacl.ports': {},
     'client.wasm.llvm': {},
     'tryserver.nacl': {},
 
     # SKIA
     'client.skia': {},
     'client.skia.android': {},
     'client.skia.fyi': {},
 
     # WebRTC
     'client.webrtc': {},
     'client.webrtc.fyi': {},
     'tryserver.webrtc': {},
   },
 }