Revert 4597 "Don't force key frame when decoding with errors"

> Don't force key frame when decoding with errors
> 
> BUG=2241
> R=stefan@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/2036004

TBR=mikhal@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2093004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4600 4adac7df-926f-26a2-2b94-8c16560cd09d
11 files changed