Implement Wheel Gesture Scrolling on OSX.

ui/events/blink/input_handler_proxy.h

 // Copyright 2013 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 UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_
 #define UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_
 
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 120 matching lines @@
   // Request a frame of animation from the InputHandler or
   // SynchronousInputHandler. They can provide that by calling Animate().
   void RequestAnimation();
 
   // Used to send overscroll messages to the browser.
   void HandleOverscroll(
       const gfx::Point& causal_event_viewport_point,
       const cc::InputHandlerScrollResult& scroll_result);
 
   // Whether to use a smooth scroll animation for this event.
-  bool ShouldAnimate(const blink::WebMouseWheelEvent& event) const;
+  bool ShouldAnimate(bool has_coarse_scroll_pixels) const;

[tdresser, 2016/03/08 14:28:53]

Can we pass has_precise_scroll_deltas? It would be more consistent with what we
pass around elsewhere.

[dtapuska, 2016/03/08 20:31:49]

done; although for the gesture case; it is a double negative; but that might be
easier to understand I guess

+
+  // Update the elastic overscroll controller with |gesture_event|.
+  void HandleScrollElasticityOverscroll(
+      const blink::WebGestureEvent& gesture_event,
+      const cc::InputHandlerScrollResult& scroll_result);
 
   scoped_ptr<blink::WebGestureCurve> fling_curve_;
   // Parameters for the active fling animation, stored in case we need to
   // transfer it out later.
   blink::WebActiveWheelFlingParameters fling_parameters_;
 
   InputHandlerProxyClient* client_;
   cc::InputHandler* input_handler_;
 
   // Time at which an active fling should expire due to a deferred cancellation
@@ skipping 47 matching lines @@
   int32_t touch_start_result_;
 
   base::TimeTicks last_fling_animate_time_;
 
   DISALLOW_COPY_AND_ASSIGN(InputHandlerProxy);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_