Adds a modified copy of talk/base to webrtc/base. It is the first step in migrating talk/base to webrtc/base.

BUG=N/A
R=andrew@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6107 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/ratetracker.h

@@ -0,0 +1,42 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_BASE_RATETRACKER_H_
+#define WEBRTC_BASE_RATETRACKER_H_
+
+#include <stdlib.h>
+#include "webrtc/base/basictypes.h"
+
+namespace rtc {
+
+// Computes instantaneous units per second.
+class RateTracker {
+ public:
+  RateTracker();
+  virtual ~RateTracker() {}
+
+  size_t total_units() const;
+  size_t units_second();
+  void Update(size_t units);
+
+ protected:
+  // overrideable for tests
+  virtual uint32 Time() const;
+
+ private:
+  size_t total_units_;
+  size_t units_second_;
+  uint32 last_units_second_time_;
+  size_t last_units_second_calc_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_BASE_RATETRACKER_H_