ext approvals: Add cross platform helper to get kid's name

Instead on relying on Ash specific User API to get supervised user's
first name add a helper method that reads the name from IdentityManager.

Use the method to display the name in extension approval flows (v1 and
v2). This is a prerequisite to enabling v2 flow in Lacros.

Bug: b:250924204
Change-Id: Ifdbb5da8c6dc037e4e35838c7bc81c30943f352a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4523310
Reviewed-by: Marc Treib <[email protected]>
Commit-Queue: Aga Wronska <[email protected]>
Reviewed-by: Nohemi Fernandez <[email protected]>
Reviewed-by: Courtney Wong <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1147284}
diff --git a/chrome/browser/supervised_user/supervised_user_test_util.cc b/chrome/browser/supervised_user/supervised_user_test_util.cc
index 8ddbfb3..7556940 100644
--- a/chrome/browser/supervised_user/supervised_user_test_util.cc
+++ b/chrome/browser/supervised_user/supervised_user_test_util.cc
@@ -4,10 +4,14 @@
 
 #include "chrome/browser/supervised_user/supervised_user_test_util.h"
 
+#include <string>
+
+#include "base/check.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_key.h"
 #include "chrome/browser/supervised_user/supervised_user_settings_service_factory.h"
 #include "components/prefs/pref_service.h"
+#include "components/signin/public/identity_manager/account_info.h"
 #include "components/supervised_user/core/browser/supervised_user_settings_service.h"
 #include "components/supervised_user/core/common/pref_names.h"
 #include "components/supervised_user/core/common/supervised_user_constants.h"
@@ -43,4 +47,15 @@
       prefs::kSupervisedUserExtensionsMayRequestPermissions, enabled);
 }
 
+void PopulateAccountInfoWithName(AccountInfo& info,
+                                 const std::string& given_name) {
+  info.given_name = given_name;
+  info.full_name = "fullname";
+  info.hosted_domain = "example.com";
+  info.locale = "en";
+  info.picture_url = "https://example.com";
+
+  CHECK(info.IsValid());
+}
+
 }  // namespace supervised_user_test_util