Revert of Delete deprecated and transitional stuff related to video frame refactoring.

webrtc/media/engine/webrtcvideoframe.h

+/*
+ *  Copyright (c) 2011 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.
+ */
+
+// TODO(nisse): Deprecated, replace cricket::WebRtcVideoFrame with
+// webrtc::VideoFrame everywhere, then delete this file. See
+// https://bugs.chromium.org/p/webrtc/issues/detail?id=5682.
+
+#ifndef WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_
+#define WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_
+
+#include <memory>
+
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/common_types.h"
+#include "webrtc/common_video/include/video_frame_buffer.h"
+#include "webrtc/media/base/videoframe.h"
+
+namespace cricket {
+
+using WebRtcVideoFrame = webrtc::VideoFrame;
+
+}  // namespace cricket
+
+#endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_