Add missing (and remove superfluous) 'explicit' from constructors.

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.
 
 // RateCounter is defined to measure average rate over a given time window.
 // Rate is reported as the sum of values recorded divided by the time window.
 // This can be used for measuring bandwidth, bitrate, etc.
 
 // This class is thread-safe.
 
 #ifndef REMOTING_BASE_RATE_COUNTER_H_
 #define REMOTING_BASE_RATE_COUNTER_H_
 
 #include <queue>
 #include <utility>
 
 #include "base/basictypes.h"
 #include "base/synchronization/lock.h"
 #include "base/time.h"
 
 namespace remoting {
 
 class RateCounter {
  public:
   // Construct a counter for a specific time window.
-  RateCounter(base::TimeDelta time_window);
+  explicit RateCounter(base::TimeDelta time_window);
 
   virtual ~RateCounter();
 
   // Record the data point.
   void Record(int64 value);
 
   // Report the rate recorded. At the beginning of recording the numbers before
   // |time_window| is reached the reported rate will not be accurate.
   double Rate();
 
@@ skipping 15 matching lines @@
 
   // Sum of values in |data_points_|.
   int64 sum_;
 
   DISALLOW_COPY_AND_ASSIGN(RateCounter);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_BASE_RATE_COUNTER_H_