WIP: Pref service user prefs.

services/preferences/BUILD.gn

 # Copyright 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.
 
 import("//services/service_manager/public/service_manifest.gni")
 
 group("tests") {
   testonly = true
   deps = [
     "//services/preferences/public/cpp/tests",
   ]
 }
 
 service_manifest("manifest") {
   name = "preferences2"
   source = "manifest.json"
 }
+
+source_set("preferences") {
+  public_deps = [
+    "//services/preferences/public/interfaces",
+  ]
+  deps = [
+    "//components/prefs",
+    "//components/user_prefs/tracked:user_prefs_tracked",
+  ]
+  sources = [
+    "user_prefs.cc",
+    "user_prefs.h",
+    "user_prefs_factory.cc",
+    "user_prefs_factory.h",
+  ]
+}
+
+source_set("test_support") {
+  testonly = true
+  deps = [
+    ":preferences",
+    "//services/preferences/public/cpp",
+    "//services/preferences/public/interfaces",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
+  sources = [
+    "user_prefs_unittest.cc",
+  ]
+}