Don't use sum for latency (#1798)

Author: SleepyBag

perf/benchmarkapps/GrpcClient/Program.cs

@@ -309,12 +309,12 @@ private static void CalculateStatistics()
 
         private static void CalculateLatency()
         {
-            BenchmarksEventSource.Register("grpc/latency/mean;http/latency/mean", Operations.Max, Operations.Sum, "Mean latency (ms)", "Mean latency (ms)", "n2");
-            BenchmarksEventSource.Register("grpc/latency/50;http/latency/50", Operations.Max, Operations.Sum, "50th percentile latency (ms)", "50th percentile latency (ms)", "n2");
-            BenchmarksEventSource.Register("grpc/latency/75;http/latency/75", Operations.Max, Operations.Sum, "75th percentile latency (ms)", "75th percentile latency (ms)", "n2");
-            BenchmarksEventSource.Register("grpc/latency/90;http/latency/90", Operations.Max, Operations.Sum, "90th percentile latency (ms)", "90th percentile latency (ms)", "n2");
-            BenchmarksEventSource.Register("grpc/latency/99;http/latency/99", Operations.Max, Operations.Sum, "99th percentile latency (ms)", "99th percentile latency (ms)", "n2");
-            BenchmarksEventSource.Register("grpc/latency/max;http/latency/max", Operations.Max, Operations.Sum, "Max latency (ms)", "Max latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/mean;http/latency/mean", Operations.Max, Operations.Max, "Mean latency (ms)", "Mean latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/50;http/latency/50", Operations.Max, Operations.Max, "50th percentile latency (ms)", "50th percentile latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/75;http/latency/75", Operations.Max, Operations.Max, "75th percentile latency (ms)", "75th percentile latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/90;http/latency/90", Operations.Max, Operations.Max, "90th percentile latency (ms)", "90th percentile latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/99;http/latency/99", Operations.Max, Operations.Max, "99th percentile latency (ms)", "99th percentile latency (ms)", "n2");
+            BenchmarksEventSource.Register("grpc/latency/max;http/latency/max", Operations.Max, Operations.Max, "Max latency (ms)", "Max latency (ms)", "n2");
             if (_options.Latency)
             {
                 var totalCount = 0;
@@ -744,4 +744,4 @@ protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage reques
             }
         }
     }
-}
+}