[DeviceService] Move PowerMonitor interfaces, client lib, impl to live in Device Service

services/device/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/cpp/service.gni")
 import("//services/service_manager/public/service_manifest.gni")
 
 source_set("lib") {
   sources = [
     "device_service.cc",
     "device_service.h",
   ]
 
   deps = [
     "//base",
-    "//device/power_monitor",
     "//device/time_zone_monitor",
+    "//services/device/power_monitor",
     "//services/service_manager/public/cpp",
   ]
 
   public_deps = [
     # TODO(blundell): This dep shouldn't be necessary at all,
     # but content_shell fails to link in the component build if
     # this isn't here as a public_dep.
     "//device/time_zone_monitor/public/interfaces",
   ]
 }
 
+source_set("tests") {
+  testonly = true
+
+  sources = [
+    "power_monitor/power_monitor_message_broadcaster_unittest.cc",
+    "public/cpp/power_monitor/power_monitor_broadcast_source_unittest.cc",
+  ]
+
+  deps = [
+    "//base",
+    "//base/test:test_support",
+    "//mojo/public/cpp/bindings",
+    "//services/device/power_monitor",
+    "//services/device/public/cpp/power_monitor",
+    "//testing/gtest",
+  ]
+}
+
 service_manifest("manifest") {
   name = "device"
   source = "manifest.json"
 }