New gn target video_frame_api.

webrtc/api/video/video_rotation.h

+/*
+ *  Copyright (c) 2015 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.
+ */
+
+#ifndef WEBRTC_API_VIDEO_VIDEO_ROTATION_H_
+#define WEBRTC_API_VIDEO_VIDEO_ROTATION_H_
+
+namespace webrtc {
+
+// enum for clockwise rotation.
+enum VideoRotation {
+  kVideoRotation_0 = 0,
+  kVideoRotation_90 = 90,
+  kVideoRotation_180 = 180,
+  kVideoRotation_270 = 270
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_VIDEO_VIDEO_ROTATION_H_