Amortize data usage using TrafficStats on Android.

components/data_usage/core/data_use_aggregator.cc

 // Copyright 2015 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 "components/data_usage/core/data_use_aggregator.h"
 
+#include <sstream>
+#include <string>
+
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "net/base/network_change_notifier.h"
 #include "net/url_request/url_request.h"
 
 namespace data_usage {
 
-DataUseAggregator::DataUseAggregator()
-    : off_the_record_tx_bytes_since_last_flush_(0),
+DataUseAggregator::DataUseAggregator(
+    scoped_ptr<DataUseAmortizer> data_use_amortizer)
+    : data_use_amortizer_(data_use_amortizer.Pass()),
+      off_the_record_tx_bytes_since_last_flush_(0),
       off_the_record_rx_bytes_since_last_flush_(0),
       is_flush_pending_(false),
       weak_ptr_factory_(this) {}
 
 DataUseAggregator::~DataUseAggregator() {}
 
 void DataUseAggregator::AddObserver(Observer* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
   observer_list_.AddObserver(observer);
 }
@@ skipping 49 matching lines @@
   off_the_record_rx_bytes_since_last_flush_ += rx_bytes;
 }
 
 base::WeakPtr<DataUseAggregator> DataUseAggregator::GetWeakPtr() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
 void DataUseAggregator::FlushBufferedDataUse() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  // TODO(sclittle): Amortize data use on supported platforms.
+  if (data_use_amortizer_) {
+    data_use_amortizer_->Amortize(&buffered_data_use_,
+                                  off_the_record_tx_bytes_since_last_flush_,
+                                  off_the_record_rx_bytes_since_last_flush_);
+  }
 
   FOR_EACH_OBSERVER(Observer, observer_list_, OnDataUse(buffered_data_use_));
 
   buffered_data_use_.clear();
   off_the_record_tx_bytes_since_last_flush_ = 0;
   off_the_record_rx_bytes_since_last_flush_ = 0;
   is_flush_pending_ = false;
 }
 
 }  // namespace data_usage