sync: remove GetAuthenticatedUsername from ProfileSyncService/SyncBackendHost.

chrome/browser/chromeos/login/login_utils.cc

Index: chrome/browser/chromeos/login/login_utils.cc
diff --git a/chrome/browser/chromeos/login/login_utils.cc b/chrome/browser/chromeos/login/login_utils.cc
index 304e73b7036005635d9979cf44e9cad64f593053..d4e5fc058e4c810683d726c1802404546b51dd59 100644
--- a/chrome/browser/chromeos/login/login_utils.cc
+++ b/chrome/browser/chromeos/login/login_utils.cc
@@ -879,6 +879,9 @@ void LoginUtilsImpl::StartSync(
 
     // Set the CrOS user by getting this constructor run with the
     // user's email on first retrieval.
+    // TODO(tim): Tidy this up once cros_user is gone (part of bug 93922).
+    user_profile->GetPrefs()->SetString(prefs::kGoogleServicesUsername,
+                                        username_);
     user_profile->GetProfileSyncService(username_)->SetPassphrase(
         password_, false);
     username_ = "";