Implement UMA log throttling for cellular connections

chrome/browser/io_thread.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_IO_THREAD_H_
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
 #include <set>
 #include <string>
 #include <unordered_set>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/net/chrome_network_delegate.h"
 #include "chrome/common/features.h"
+#include "components/metrics/data_use_tracker.h"
 #include "components/prefs/pref_member.h"
 #include "components/ssl_config/ssl_config_service_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/browser_thread_delegate.h"
 #include "net/base/network_change_notifier.h"
 #include "net/http/http_network_session.h"
 
 class PrefProxyConfigTracker;
 class PrefService;
 class PrefRegistrySimple;
@@ skipping 554 matching lines @@
       system_url_request_context_getter_;
 
   // True if SPDY is disabled by policy.
   bool is_spdy_disabled_by_policy_;
 
   // True if QUIC is allowed by policy.
   bool is_quic_allowed_by_policy_;
 
   const base::TimeTicks creation_time_;
 
+  // Callback for updating data use prefs which needs to be initialized on UI
+  // thread and passed to // |ChromeNetworkDelegate|.

[Alexei Svitkine (slow), 2016/03/31 04:32:25]

Nit: Remove extra //

[gayane -on leave until 09-2017, 2016/03/31 17:54:57]

Done.

+  metrics::UpdateUsagePrefCallbackType metrics_data_use_forwarder_;
+
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_