Revert of Fix issue of localDescription and remoteDescription getter.

Revert of Fix issue of localDescription and remoteDescription getter. (patchset #8 id:140001 of https://codereview.chromium.org/1010393002/)

Reason for revert:
This patch breaks WebRTC browser tests (and, indeed, most WebRTC functionality, for instance apprtc.appspot.com calls).

Original issue's description:
> Fix issue of localDescription and remoteDescription getter.
> 
> Current implementation returns a new RTCSessionDescription instance
> when get localDescription and remoteDescription value. This causes error
> of Javascript equality check.
> 
> The CL fixes above issue.
> 
> BUG=
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195576

TBR=tommi@chromium.org,haraken@chromium.org,jl@opera.com,jochen@chromium.org,tommyw@chromium.org,yukishiino@chromium.org,bashi@chromium.org,changbin.shao@intel.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195778

[phoglund_chromium, 2015-05-22 11:12:52]

Created Revert of Fix issue of localDescription and remoteDescription getter.

[commit-bot: I haz the power, 2015-05-22 11:13:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1152173003/1

[haraken, 2015-05-22 11:13:47]

LGTM

That CL caused a couple of issues. It would be reasonable to fix them and reland
it.

[phoglund_chromium, 2015-05-22 11:14:24]

On 2015/05/22 11:13:26, I haz the power (commit-bot) wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1152173003/1

Tracked by bug https://code.google.com/p/chromium/issues/detail?id=491075.

[commit-bot: I haz the power, 2015-05-22 11:14:46]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=195778