Move common VideoPacket initialization into VideoEncoderHelper.

remoting/codec/video_encoder_helper.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_CODEC_VIDEO_ENCODER_HELPER_H_
+#define REMOTING_CODEC_VIDEO_ENCODER_HELPER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
+
+namespace webrtc {
+class DesktopFrame;
+class DesktopRegion;
+}
+
+namespace remoting {
+
+class VideoPacket;
+
+class VideoEncoderHelper {
+ public:
+  VideoEncoderHelper();
+
+  // Returns a new VideoPacket with common fields (e.g. capture_time_ms, rects
+  // list, frame shape if any) initialized based on the supplied |frame|.
+  // Screen width and height will be set iff |frame|'s size differs from that
+  // of the previously-supplied frame.
+  scoped_ptr<VideoPacket> CreateVideoPacket(const webrtc::DesktopFrame& frame);
+
+  // Returns a new VideoPacket with the common fields populated from |frame|,
+  // but the updated rects overridden by |updated_region|. This is useful for
+  // encoders which alter the updated region e.g. by expanding it to macroblock
+  // boundaries.
+  scoped_ptr<VideoPacket> CreateVideoPacketWithUpdatedRegion(
+      const webrtc::DesktopFrame& frame,
+      const webrtc::DesktopRegion& updated_region);
+ private:
+  // The most recent screen size. Used to detect screen size changes.
+  webrtc::DesktopSize screen_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(VideoEncoderHelper);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_CODEC_VIDEO_ENCODER_HELPER_H_