Added send-thresholding and fixed text packet dumping.  Also a little squelch for the over-max-MTU log spam we see in there.

BUG=https://code.google.com/p/webrtc/issues/detail?id=4468
R=pthatcher@chromium.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1304063006 .

Cr-Commit-Position: refs/heads/master@{#9812}
3 files changed