Periodically remove old pending navigation entries.

components/data_use_measurement/core/data_use.h

 // Copyright 2016 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 COMPONENTS_DATA_USE_MEASUREMENT_CORE_DATA_USE_H_
 #define COMPONENTS_DATA_USE_MEASUREMENT_CORE_DATA_USE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 20 matching lines @@
   const std::string& description() const { return description_; }
 
   void set_description(const std::string& description) {
     description_ = description;
   }
 
   int64_t total_bytes_received() const { return total_bytes_received_; }
 
   int64_t total_bytes_sent() const { return total_bytes_sent_; }
 
+  base::Time start_time() const { return start_time_; }
+
  private:
   friend class DataUseRecorder;
 
   GURL url_;
   std::string description_;
 
   int64_t total_bytes_sent_;
   int64_t total_bytes_received_;
 
+  // When this data use started.
+  base::Time start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(DataUse);
 };
 
 }  // namespace data_use_measurement
 
 #endif  // COMPONENTS_DATA_USE_MEASUREMENT_CORE_DATA_USE_H_