Remove locks in SendSideBandwidthEstimation since those are only accessed while owning locks in
BitrateControllerImpl (excluding AvailableBandwidth).

 + Refactor BitrateController logic around LowRate allocation so access to SendSideBandwidthEstimation
is clear.
 + Refactor NormalRateAllocation away from OnNetworkChange.
 + Annotate BitrateController locks.

R=henrik.lundin@webrtc.org, stefan@webrtc.org
BUG=3065

Review URL: https://webrtc-codereview.appspot.com/10129004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5749 4adac7df-926f-26a2-2b94-8c16560cd09d
4 files changed