Update first-sync-delay metric name to be consistent with others and add it to

chrome/browser/sync/profile_sync_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/profile_sync_service.h"
 
 #include <cstddef>
 #include <map>
 #include <vector>
 
@@ skipping 672 matching lines @@
     else
       ShutdownImpl(syncer::STOP_SYNC);
   }
 
   backend_mode_ = mode;
 
   if (backend_mode_ == BACKUP)
     backup_start_time_ = base::Time::Now();
 
   if (backend_mode_ == SYNC && !backup_start_time_.is_null()) {
-    UMA_HISTOGRAM_TIMES("first-sync-delay-by-backup",
-                        base::Time::Now() - backup_start_time_);
+    UMA_HISTOGRAM_MEDIUM_TIMES("Sync.FirstSyncDelayByBackup",
+                               base::Time::Now() - backup_start_time_);
     backup_start_time_ = base::Time();
   }
 
   if (backend_mode_ == ROLLBACK)
     ClearBrowsingDataSinceFirstSync();
   else if (backend_mode_ == SYNC)
     CheckSyncBackupIfNeeded();
 
   base::FilePath sync_folder = backend_mode_ == SYNC ?
       base::FilePath(kSyncDataFolderName) :
@@ skipping 2057 matching lines @@
                  true));
 }
 
 bool ProfileSyncService::NeedBackup() const {
   return need_backup_;
 }
 
 base::Time ProfileSyncService::GetDeviceBackupTimeForTesting() const {
   return backend_->GetSyncedDeviceTracker()->GetLocalDeviceBackupTime();
 }