Add DeviceADPolicyManager to provide AD policy.

chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc

Index: chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
diff --git a/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc b/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
index 2edff5afe3d251c826d78dc795bcbbdfca6a8c74..923f5288fbbd698296715252a85249bb9c5d8866 100644
--- a/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
+++ b/chrome/browser/chromeos/login/users/chrome_user_manager_impl.cc
@@ -219,20 +219,23 @@ ChromeUserManagerImpl::ChromeUserManagerImpl()
   multi_profile_user_controller_.reset(
       new MultiProfileUserController(this, GetLocalState()));
 
-  policy::BrowserPolicyConnectorChromeOS* connector =
-      g_browser_process->platform_part()->browser_policy_connector_chromeos();
-  avatar_policy_observer_.reset(new policy::CloudExternalDataPolicyObserver(
-      cros_settings_,
-      connector->GetDeviceLocalAccountPolicyService(),
-      policy::key::kUserAvatarImage,
-      this));
-  avatar_policy_observer_->Init();
+  policy::DeviceLocalAccountPolicyService* device_local_account_policy_service =
+      g_browser_process->platform_part()
+          ->browser_policy_connector_chromeos()
+          ->GetDeviceLocalAccountPolicyService();
+  if (!device_local_account_policy_service) {
+    return;
+  }
 
-  wallpaper_policy_observer_.reset(new policy::CloudExternalDataPolicyObserver(
-      cros_settings_,
-      connector->GetDeviceLocalAccountPolicyService(),
-      policy::key::kWallpaperImage,
-      this));
+  avatar_policy_observer_ =
+      base::MakeUnique<policy::CloudExternalDataPolicyObserver>(
+          cros_settings_, device_local_account_policy_service,
+          policy::key::kUserAvatarImage, this);
+  avatar_policy_observer_->Init();
+  wallpaper_policy_observer_ =
+      base::MakeUnique<policy::CloudExternalDataPolicyObserver>(
+          cros_settings_, device_local_account_policy_service,
+          policy::key::kWallpaperImage, this);
   wallpaper_policy_observer_->Init();
 }