Decouple Metrics Initialization from IO Thread Initialization

chrome/browser/profiles/profile_impl_io_data.h

 // 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.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_IMPL_IO_DATA_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_IMPL_IO_DATA_H_
 
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
@@ skipping 216 matching lines @@
 
   mutable std::unique_ptr<net::SdchOwner> sdch_policy_;
 
   mutable std::unique_ptr<previews::PreviewsIOData> previews_io_data_;
 
   // Parameters needed for isolated apps.
   base::FilePath profile_path_;
   int app_cache_max_size_;
   int app_media_cache_max_size_;
 
+  // Callback for updating data use prefs which needs to be initialized on UI
+  // thread and passed to the network delegate.
+  const metrics::UpdateUsagePrefCallbackType metrics_data_use_forwarder_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileImplIOData);
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_IMPL_IO_DATA_H_