user_manager component: Add UserManagerBase class.

chrome/browser/chromeos/policy/device_local_account_browsertest.cc

Index: chrome/browser/chromeos/policy/device_local_account_browsertest.cc
diff --git a/chrome/browser/chromeos/policy/device_local_account_browsertest.cc b/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
index 1861cb92cade075dc77fb2bf011d9a81d2c564e7..14d1d9bb728241fb226e6ef325ead5a7f9e1f57e 100644
--- a/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
+++ b/chrome/browser/chromeos/policy/device_local_account_browsertest.cc
@@ -45,8 +45,8 @@
 #include "chrome/browser/chromeos/login/users/avatar/user_image_manager.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_manager_impl.h"
 #include "chrome/browser/chromeos/login/users/avatar/user_image_manager_test_util.h"
+#include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/user_manager.h"
-#include "chrome/browser/chromeos/login/users/user_manager_impl.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/cloud_external_data_manager_base_test_util.h"
@@ -872,8 +872,8 @@ IN_PROC_BROWSER_TEST_F(DeviceLocalAccountTest, ExternalData) {
   // verify that the underlying policy subsystem will start a fetch
   // without this request as well, the chromeos::UserManager must be
   // prevented from seeing the policy change.
-  reinterpret_cast<chromeos::UserManagerImpl*>(chromeos::UserManager::Get())->
-      StopPolicyObserverForTesting();
+  reinterpret_cast<chromeos::ChromeUserManager*>(chromeos::UserManager::Get())
+      ->StopPolicyObserverForTesting();
 
   UploadDeviceLocalAccountPolicy();
   AddPublicSessionToDevicePolicy(kAccountId1);