Change 'mute' parameter of MediaChannel::SetAudioSend()/SetVideoSend() to 'enable'.

Change 'mute' parameter of MediaChannel::SetAudioSend()/SetVideoSend() to 'enable'.

BUG=webrtc:4690
Committed: https://crrev.com/dfc8f4ff8731390828884a0a91b99e51f2950275
Cr-Commit-Position: refs/heads/master@{#10130}

[the sun, 2015-09-29 11:27:30]

solenberg@webrtc.org changed reviewers:
+ pthatcher@webrtc.org

[pthatcher1, 2015-09-30 22:49:20]

lgtm

[the sun, 2015-10-01 08:30:07]

The CQ bit was checked by solenberg@webrtc.org

[the sun, 2015-10-01 08:30:07]

The patchset sent to the CQ was uploaded after l-g-t-m from pthatcher@webrtc.org
Link to the patchset: https://codereview.webrtc.org/1378513003/#ps20001 (title:
"rebase")

[commit-bot: I haz the power, 2015-10-01 08:30:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1378513003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1378513003/20001

[commit-bot: I haz the power, 2015-10-01 09:31:15]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-01 09:32:49]

Patchset 2 (id:??) landed as
https://crrev.com/dfc8f4ff8731390828884a0a91b99e51f2950275
Cr-Commit-Position: refs/heads/master@{#10130}