Round Rate computations from RateTracker.

BUG=534221
R=asapersson@webrtc.org, pbos@webrtc.org, pthatcher@webrtc.org

Review URL: https://codereview.webrtc.org/1410533004 .

Cr-Original-Commit-Position: refs/heads/master@{#10592}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ad13d2f8178af5efbe516184995af02a171ec66a

base/ratetracker.cc

diff --git a/base/ratetracker.cc b/base/ratetracker.cc
index 5cb4490..35521a8 100644
--- a/base/ratetracker.cc
+++ b/base/ratetracker.cc
@@ -73,8 +73,9 @@
   size_t start_bucket = NextBucketIndex(current_bucket_ + buckets_to_skip);
   // Only count a portion of the first bucket according to how much of the
   // first bucket is within the current interval.
-  size_t total_samples = sample_buckets_[start_bucket] *
-      (bucket_milliseconds_ - milliseconds_to_skip) /
+  size_t total_samples = ((sample_buckets_[start_bucket] *
+      (bucket_milliseconds_ - milliseconds_to_skip)) +
+      (bucket_milliseconds_ >> 1)) /
       bucket_milliseconds_;
   // All other buckets in the interval are counted in their entirety.
   for (size_t i = NextBucketIndex(start_bucket);