Update native plugin dll for turn servers and video.

webrtc/examples/unityplugin/video_observer.cc

+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/examples/unityplugin/video_observer.h"
+
+void VideoObserver::SetVideoCallback(I420FRAMEREADY_CALLBACK callback) {
+  std::lock_guard<std::mutex> lock(mutex);
+  OnI420FrameReady = callback;
+}
+
+void VideoObserver::OnFrame(const webrtc::VideoFrame& frame) {
+  std::unique_lock<std::mutex> lock(mutex);
+  rtc::scoped_refptr<webrtc::PlanarYuvBuffer> buffer(
+      frame.video_frame_buffer()->ToI420());
+  if (OnI420FrameReady) {
+    OnI420FrameReady(buffer->DataY(), buffer->DataU(), buffer->DataV(),
+                     buffer->StrideY(), buffer->StrideU(), buffer->StrideV(),
+                     frame.width(), frame.height());
+  }
+}