Fix bug in how send timestamps are converted to 24 bits.

webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc

Index: webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc b/webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc
index 9d86ba31be3e18bfb4fdd5d929ab1c98ff51c84c..cb8d0db5c70cf626efd2dcf9a956442ee82d197c 100644
--- a/webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc
+++ b/webrtc/modules/remote_bitrate_estimator/bwe_simulations.cc
@@ -36,7 +36,7 @@ class BweSimulation : public BweTest,
     VerboseLogging(true);
   }
 
-  Random random_;
+  test::Random random_;
 
  private:
   RTC_DISALLOW_COPY_AND_ASSIGN(BweSimulation);