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, pthatcher@webrtc.org

Review URL: https://codereview.webrtc.org/1266033005 .

Cr-Commit-Position: refs/heads/master@{#9788}
3 files changed