The known clients (GetStats and UMA histogram in Chrome) use at least 5 second aggregation window. There is no particular value in calculating the metrics more often.
The CL also includes a small refactoring moving a declaration inside an if statement.
BUG=2994
TEST=N/A
R=kwiberg@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/40219004
Cr-Commit-Position: refs/heads/master@{#8619}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8619 4adac7df-926f-26a2-2b94-8c16560cd09d
d7a212e8b9