Revert 5737 "Add system wrapper dependency to libjingle targets."

Adding additional dependency is not required for libjingle targets.

> Add system wrapper dependency to libjingle targets.
> This is necessary to handle usage of STR_CASE_CMP in
> common_types.h ( as in https://webrtc-codereview.appspot.com/10099005/)
> 
> TBR=wu@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/10309004

TBR=mallinath@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/10379004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5744 4adac7df-926f-26a2-2b94-8c16560cd09d
Roll libvpx 254609:258445.

Picks up the suppression of -fstack-protector-all on iOS to avoid a crash.

BUG=3067
R=wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/10369004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5745 4adac7df-926f-26a2-2b94-8c16560cd09d
Adding operator== and != methods for CodecInst and VideoCodec structures.

R=juberti@google.com, mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/10099005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5746 4adac7df-926f-26a2-2b94-8c16560cd09d