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

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 850bcbe8556ef28d0276a01e56bbd382f1a81a31

sippet/talk,sippet/talk,sippet/talk,sippet/talk,sippet/talk