Basic UkmService implementation

components/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//printing/features/features.gni")
 import("//rlz/features/features.gni")
 import("//testing/test.gni")
@@ skipping 125 matching lines @@
     "//components/supervised_user_error_page:unit_tests",
     "//components/sync:unit_tests",
     "//components/sync_bookmarks:unit_tests",
     "//components/sync_preferences:unit_tests",
     "//components/sync_sessions:unit_tests",
     "//components/task_scheduler_util/common:unit_tests",
     "//components/test:test_support",
     "//components/translate/core/browser:unit_tests",
     "//components/translate/core/common:unit_tests",
     "//components/translate/core/language_detection:unit_tests",
+    "//components/ukm:unit_tests",
     "//components/undo:unit_tests",
     "//components/update_client:unit_tests",
     "//components/upload_list:unit_tests",
     "//components/url_formatter:unit_tests",
     "//components/url_matcher:unit_tests",
     "//components/user_prefs/tracked:unit_tests",
     "//components/variations:unit_tests",
     "//components/variations/service:unit_tests",
     "//components/web_resource:unit_tests",
     "//components/webdata/common:unit_tests",
@@ skipping 342 matching lines @@
       "//testing/perf",
       "//url",
     ]
 
     if (!is_ios) {
       sources += [ "discardable_memory/common/discardable_shared_memory_heap_perftest.cc" ]
       deps += [ "//components/discardable_memory/common" ]
     }
   }
 }