[CRD iOS] Injecting scroll events w/ fling animation

remoting/client/ui/gesture_interpreter.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_UI_GESTURE_INTERPRETER_H_
 #define REMOTING_CLIENT_UI_GESTURE_INTERPRETER_H_
 
 #include <memory>
 
 #include "remoting/client/ui/desktop_viewport.h"
@@ skipping 31 matching lines @@
   void TwoFingerTap(float x, float y);
 
   // Caller is expected to call both Pan() and LongPress() when long-press is in
   // progress.
   void LongPress(float x, float y, GestureState state);
 
   // Called when the user has just done a one-finger pan (no long-press or
   // pinching) and the pan gesture still has some final velocity.
   void OneFingerFling(float velocity_x, float velocity_y);
 
+  // Called during a two-finger scroll (panning without pinching) gesture.
+  void Scroll(float x, float y, float dx, float dy);
+
+  // Called when the user has just done a scroll gesture and the scroll gesture
+  // still has some final velocity.
+  void ScrollWithVelocity(float velocity_x, float velocity_y);
+
   // Called to process one animation frame.
   void ProcessAnimations();
 
   void OnSurfaceSizeChanged(int width, int height);
   void OnDesktopSizeChanged(int width, int height);
 
  private:
   void PanWithoutAbortAnimations(float translation_x, float translation_y);
 
+  void ScrollWithoutAbortAnimations(float dx, float dy);
+
   void AbortAnimations();
 
   void InjectMouseClick(float x,
                         float y,
                         protocol::MouseEvent_MouseButton button);
 
   // Tracks the touch point and gets back the cursor position from the input
   // strategy.
   ViewMatrix::Point TrackAndGetPosition(float touch_x, float touch_y);
 
   // If the cursor is visible, send the cursor position from the input strategy
   // to the renderer.
   void SetCursorPositionOnRenderer();
 
   // Starts the given feedback at (cursor_x, cursor_y) if the feedback radius
   // is non-zero.
   void StartInputFeedback(float cursor_x,
                           float cursor_y,
                           InputStrategy::InputFeedbackType feedback_type);
 
   std::unique_ptr<InputStrategy> input_strategy_;
   DesktopViewport viewport_;
   RendererProxy* renderer_;
   ChromotingSession* input_stub_;
   bool is_dragging_mode_ = false;
 
   FlingAnimation pan_animation_;
+  FlingAnimation scroll_animation_;
 
   // GestureInterpreter is neither copyable nor movable.
   GestureInterpreter(const GestureInterpreter&) = delete;
   GestureInterpreter& operator=(const GestureInterpreter&) = delete;
 };
 
 }  // namespace remoting
 #endif  // REMOTING_CLIENT_UI_GESTURE_INTERPRETER_H_