Basic UkmService implementation

components/ukm/ukm_pref_names.cc

Index: components/ukm/ukm_pref_names.cc
diff --git a/components/ukm/ukm_pref_names.cc b/components/ukm/ukm_pref_names.cc
new file mode 100644
index 0000000000000000000000000000000000000000..abf38055ba1fd429b1c55023cfd8e38c77a301e6
--- /dev/null
+++ b/components/ukm/ukm_pref_names.cc
@@ -0,0 +1,17 @@
+// Copyright 2017 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.
+
+#include "components/ukm/ukm_pref_names.h"
+
+namespace ukm {
+namespace prefs {
+
+// A random value unique for each chrome install.

[Alexei Svitkine (slow), 2017/01/10 17:37:19]

Mention what the type is.

[Steven Holte, 2017/01/10 22:52:44]

Done.

+const char kUkmClientId[] = "ukm.client_id";
+
+// Preference which stores serialized UKM logs to be uploaded.
+const char kUkmPersistedLogs[] = "ukm.persisted_logs";
+
+}  // namespace prefs
+}  // namespace ukm