Revert of Add iceTransports to RTCConfiguration and add RTCOfferOptions for CreateOffer. (https://codereview.chromium.org/361093002/)

Reason for revert:
The following tests fail on Mac:

fast/mediastream/RTCPeerConnection-createOffer.html
fast/mediastream/RTCPeerConnection.html

Original issue's description:
> Add iceTransports to RTCConfiguration and add RTCOfferOptions for CreateOffer.
> 
> BUG=https://code.google.com/p/webrtc/issues/detail?id=3282
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178184

TBR=grunell@chromium.org,tommi@chromium.org,jiayl@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=https://code.google.com/p/webrtc/issues/detail?id=3282

Review URL: https://codereview.chromium.org/393053002

git-svn-id: svn://svn.chromium.org/blink/trunk@178192 bbb929c8-8fbe-4397-9dbb-9b2b20218538