Cleanup RateCounter

remoting/base/rate_counter.h

 // Copyright (c) 2011 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 REMOTING_BASE_RATE_COUNTER_H_
 #define REMOTING_BASE_RATE_COUNTER_H_
 
 #include <stdint.h>
 
 #include <queue>
 #include <utility>
 
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
+#include "base/time/default_tick_clock.h"
+#include "base/time/tick_clock.h"
 #include "base/time/time.h"
 
 namespace remoting {
 
 // Measures average rate per second of a sequence of point rate samples
 // over a specified time window. This can be used to measure bandwidth, frame
 // rates, etc.
 class RateCounter : public base::NonThreadSafe {
  public:
   // Constructs a rate counter over the specified |time_window|.
   explicit RateCounter(base::TimeDelta time_window);
   virtual ~RateCounter();
 
   // Records a point event count to include in the rate.
   void Record(int64_t value);
 
   // Returns the rate-per-second of values recorded over the time window.
   // Note that rates reported before |time_window| has elapsed are not accurate.
   double Rate();
 
-  // Overrides the current time for testing.
-  void SetCurrentTimeForTest(base::Time current_time);
+  void set_tick_clock_for_tests(base::TickClock* tick_clock) {
+    tick_clock_ = tick_clock;
+  }
 
  private:
   // Type used to store data points with timestamps.
-  typedef std::pair<base::Time, int64_t> DataPoint;
+  typedef std::pair<base::TimeTicks, int64_t> DataPoint;
 
   // Removes data points more than |time_window| older than |current_time|.
-  void EvictOldDataPoints(base::Time current_time);
-
-  // Returns the current time specified for test, if set, or base::Time::Now().
-  base::Time CurrentTime() const;
+  void EvictOldDataPoints(base::TimeTicks current_time);
 
   // Time window over which to calculate the rate.
   const base::TimeDelta time_window_;
 
   // Queue containing data points in the order in which they were recorded.
   std::queue<DataPoint> data_points_;
 
   // Sum of values in |data_points_|.
   int64_t sum_;
 
-  // If set, used to calculate the running average, in place of Now().
-  base::Time current_time_for_test_;
+  base::DefaultTickClock default_tick_clock_;
+  base::TickClock* tick_clock_ = &default_tick_clock_;
 
   DISALLOW_COPY_AND_ASSIGN(RateCounter);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_BASE_RATE_COUNTER_H_