Remove frame_callback.h include in webrtcvie.h.
Remove frame_callback.h include in webrtcvie.h.

This file is about to be moved and it's not really needed. The class
I420FrameCallback is forward declared inside vie_image_process.h and
only used in talk/ for a no-op implementation that doesn't access the
pointer.

BUG=
R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/3039004

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@5041 4adac7df-926f-26a2-2b94-8c16560cd09d

ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,TimothyGu/libilbc,mwgoldsmith/libilbc,mwgoldsmith/libilbc,mwgoldsmith/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,mwgoldsmith/ilbc,TimothyGu/libilbc,mwgoldsmith/ilbc