This CL replaces user_manager::UserID with AccountId.

components/wallpaper/wallpaper_manager_base.cc

Index: components/wallpaper/wallpaper_manager_base.cc
diff --git a/components/wallpaper/wallpaper_manager_base.cc b/components/wallpaper/wallpaper_manager_base.cc
index 3e0b014eca98e714f0cc948906aaf64a9e20632e..96f8dfcaa28729d4f66ba732f91f2ca1f7255ca4 100644
--- a/components/wallpaper/wallpaper_manager_base.cc
+++ b/components/wallpaper/wallpaper_manager_base.cc
@@ -27,6 +27,7 @@
 #include "chromeos/cryptohome/async_method_caller.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/login/user_names.h"
+#include "components/signin/core/account_id/account_id.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_image/user_image.h"
 #include "components/user_manager/user_manager.h"
@@ -500,8 +501,8 @@ WallpaperManagerBase::~WallpaperManagerBase() {
 void WallpaperManagerBase::SetPolicyControlledWallpaper(
     const std::string& user_id,
     const user_manager::UserImage& user_image) {
-  const user_manager::User* user =
-      user_manager::UserManager::Get()->FindUser(user_id);
+  const user_manager::User* user = user_manager::UserManager::Get()->FindUser(
+      AccountId::FromUserEmail(user_id));
   if (!user) {
     NOTREACHED() << "Unknown user.";
     return;
@@ -885,7 +886,7 @@ void WallpaperManagerBase::MoveCustomWallpapersSuccess(
     info.location = base::FilePath(user_id_hash).Append(info.location).value();
     bool is_persistent =
         !user_manager::UserManager::Get()->IsUserNonCryptohomeDataEphemeral(
-            user_id);
+            AccountId::FromUserEmail(user_id));
     SetUserWallpaperInfo(user_id, info, is_persistent);
   }
 }