Remove TimeToSendPacket and TimeToSendPadding from the default module.

Thie CL moves the default RTP module logic for TimeToSendPacket and
TimeToSendPadding to PayloadRouter class and asserts on usage of the
default module.

BUG=769
TEST=New unittest.
R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/33319004

Cr-Original-Commit-Position: refs/heads/master@{#8383}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 290cb56dcaf29dc15cc3fffc10565d2c3fb7095d
7 files changed