[CRD iOS] Move UI stuff into a subdirectory

remoting/client/fling_tracker.h

-// Copyright 2017 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_CLIENT_FLING_TRACKER_H_
-#define REMOTING_CLIENT_FLING_TRACKER_H_
-
-#include "base/time/time.h"
-
-namespace remoting {
-
-// A class for tracking the positions of an object moving through a viscous
-// liquid.
-class FlingTracker {
- public:
-  // time_constant: The larger the number the longer it takes to fling.
-  explicit FlingTracker(float time_constant);
-
-  ~FlingTracker();
-
-  // Sets the position of the object and start fling. This will reset the
-  // existing fling.
-  void StartFling(float velocity_x, float velocity_y);
-
-  void StopFling();
-
-  bool IsFlingInProgress() const;
-
-  // time_elapsed: The time elapsed since the animation has started.
-  // Moves forward the object to catch up with |time_elapsed|. The change in
-  // positions will be written to |dx| and |dy|.
-  // Returns true if the fling is still in progress at |time_elapsed|, false
-  // otherwise, in which case |dx| and |dy| will not be touched.
-  bool TrackMovement(base::TimeDelta time_elapsed, float* dx, float* dy);
-
- private:
-  float time_constant_;
-  float initial_speed_rate_ = 0.f;
-  float velocity_ratio_x_ = 0.f;
-  float velocity_ratio_y_ = 0.f;
-  float previous_position_x_ = 0.f;
-  float previous_position_y_ = 0.f;
-
-  base::TimeTicks start_time_;
-
-  // FlingTracker is neither copyable nor movable.
-  FlingTracker(const FlingTracker&) = delete;
-  FlingTracker& operator=(const FlingTracker&) = delete;
-};
-
-}  // namespace remoting
-#endif  // REMOTING_CLIENT_FLING_TRACKER_H_