Remove webrtc::DesktopCapturer::Callback::CreateSharedMemory() overrides.

remoting/protocol/webrtc_frame_scheduler.cc

Index: remoting/protocol/webrtc_frame_scheduler.cc
diff --git a/remoting/protocol/webrtc_frame_scheduler.cc b/remoting/protocol/webrtc_frame_scheduler.cc
index a9f25cb1dc1c4cdc6ba888d386f0078149cb3d73..bdc602272304ff5a107ee859df130ff75185e11c 100644
--- a/remoting/protocol/webrtc_frame_scheduler.cc
+++ b/remoting/protocol/webrtc_frame_scheduler.cc
@@ -84,11 +84,6 @@ bool WebRtcFrameScheduler::ClearAndGetKeyFrameRequest() {
   return key_frame_request;
 }
 
-webrtc::SharedMemory* WebRtcFrameScheduler::CreateSharedMemory(size_t size) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  return nullptr;
-}
-
 void WebRtcFrameScheduler::OnCaptureCompleted(webrtc::DesktopFrame* frame) {
   DCHECK(thread_checker_.CalledOnValidThread());