Refactor: Inject StatisticsProvider as a dependency of DeviceCloudPolicyInitializer.

chrome/browser/chromeos/login/wizard_controller_browsertest.cc

Index: chrome/browser/chromeos/login/wizard_controller_browsertest.cc
diff --git a/chrome/browser/chromeos/login/wizard_controller_browsertest.cc b/chrome/browser/chromeos/login/wizard_controller_browsertest.cc
index 31e3d722a8e9471702aab084892468f6b7eabbe2..706e0397e1c5e22943ed1ba80601ed6b8e8ee117 100644
--- a/chrome/browser/chromeos/login/wizard_controller_browsertest.cc
+++ b/chrome/browser/chromeos/login/wizard_controller_browsertest.cc
@@ -726,9 +726,10 @@ class WizardControllerDeviceStateTest : public WizardControllerFlowTest {
                             std::string(),
                             std::string(),
                             policy::DEVICE_MODE_NOT_SET) {
-    fake_statistics_provider_.SetMachineStatistic("serial_number", "test");
-    fake_statistics_provider_.SetMachineStatistic(system::kActivateDateKey,
-                                                  "2000-01");
+    fake_statistics_provider_.SetMachineStatistic(
+        system::kSerialNumberKey, "test");
+    fake_statistics_provider_.SetMachineStatistic(
+        system::kActivateDateKey, "2000-01");
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {