Add support for multiple report blocks.

Use a weighted average of fraction loss for bandwidth estimation.

TEST=trybots and vie_auto_test --automated
BUG=1811
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2198004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4762 4adac7df-926f-26a2-2b94-8c16560cd09d
11 files changed