Move frame drop functionality in VideoAdapter into a separate class.

This class will replace modules/video_coding/utility/framerate_controller.h

Bug: webrtc:13031
Change-Id: I8faa9c3c158b7c5ab0618e3504224c7e00f8e0b1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227350
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34802}

modules/video_coding/utility/framerate_controller_deprecated.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright (c) 2018 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 MODULES_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_
+#define MODULES_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_
+
+#include <stdint.h>
+
+#include "absl/types/optional.h"
+#include "rtc_base/rate_statistics.h"
+
+namespace webrtc {
+
+// Please use webrtc::FramerateController instead.
+class FramerateControllerDeprecated {
+ public:
+  explicit FramerateControllerDeprecated(float target_framerate_fps);
+
+  void SetTargetRate(float target_framerate_fps);
+  float GetTargetRate();
+
+  // Advices user to drop next frame in order to reach target framerate.
+  bool DropFrame(uint32_t timestamp_ms) const;
+
+  void AddFrame(uint32_t timestamp_ms);
+
+  void Reset();
+
+ private:
+  absl::optional<float> Rate(uint32_t timestamp_ms) const;
+
+  absl::optional<float> target_framerate_fps_;
+  absl::optional<uint32_t> last_timestamp_ms_;
+  uint32_t min_frame_interval_ms_;
+  RateStatistics framerate_estimator_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_UTILITY_FRAMERATE_CONTROLLER_DEPRECATED_H_