Touchpad and wheel scroll latching for ChromeOS behind flag.

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 <memory>
 
 #include "base/containers/hash_tables.h"
@@ skipping 44 matching lines @@
 
   InputHandlerProxy(cc::InputHandler* input_handler,
                     InputHandlerProxyClient* client);
   ~InputHandlerProxy() override;
 
   InputScrollElasticityController* scroll_elasticity_controller() {
     return scroll_elasticity_controller_.get();
   }
 
   void set_smooth_scroll_enabled(bool value) { smooth_scroll_enabled_ = value; }
+  void set_touchpad_and_wheel_scroll_latching_enabled(bool value) {
+    touchpad_and_wheel_scroll_latching_enabled_ = value;
+  }
 
   enum EventDisposition {
     DID_HANDLE,
     DID_NOT_HANDLE,
     DID_NOT_HANDLE_NON_BLOCKING_DUE_TO_FLING,
     DID_HANDLE_NON_BLOCKING,
     DROP_EVENT
   };
   using EventDispositionCallback =
       base::Callback<void(EventDisposition,
@@ skipping 45 matching lines @@
   friend class test::InputHandlerProxyTest;
   friend class test::InputHandlerProxyEventQueueTest;
 
   void DispatchSingleInputEvent(std::unique_ptr<EventWithCallback>,
                                 const base::TimeTicks);
   void DispatchQueuedInputEvents();
 
   // Helper functions for handling more complicated input events.
   EventDisposition HandleMouseWheel(
       const blink::WebMouseWheelEvent& event);
-  EventDisposition ScrollByMouseWheel(
+  EventDisposition FlingScrollByMouseWheel(
       const blink::WebMouseWheelEvent& event,
       cc::EventListenerProperties listener_properties);
   EventDisposition HandleGestureScrollBegin(
       const blink::WebGestureEvent& event);
   EventDisposition HandleGestureScrollUpdate(
       const blink::WebGestureEvent& event);
   EventDisposition HandleGestureScrollEnd(
       const blink::WebGestureEvent& event);
   EventDisposition HandleGestureFlingStart(
       const blink::WebGestureEvent& event);
@@ skipping 87 matching lines @@
 
   // Non-zero only within the scope of |scrollBy|.
   gfx::Vector2dF current_fling_velocity_;
 
   // Used to animate rubber-band over-scroll effect on Mac.
   std::unique_ptr<InputScrollElasticityController>
       scroll_elasticity_controller_;
 
   bool smooth_scroll_enabled_;
   bool uma_latency_reporting_enabled_;
+  bool touchpad_and_wheel_scroll_latching_enabled_;
 
   // The merged result of the last touch start with previous touch starts.
   // This value will get returned for subsequent TouchMove events to allow
   // passive events not to block scrolling.
   int32_t touch_start_result_;
 
   base::TimeTicks last_fling_animate_time_;
 
   // Used to record overscroll notifications while an event is being
   // dispatched.  If the event causes overscroll, the overscroll metadata can be
   // bundled in the event ack, saving an IPC.  Note that we must continue
   // supporting overscroll IPC notifications due to fling animation updates.
   std::unique_ptr<DidOverscrollParams> current_overscroll_params_;
 
   std::unique_ptr<CompositorThreadEventQueue> compositor_event_queue_;
   bool has_ongoing_compositor_scroll_pinch_;
 
   std::unique_ptr<base::TickClock> tick_clock_;
 
   DISALLOW_COPY_AND_ASSIGN(InputHandlerProxy);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_BLINK_INPUT_HANDLER_PROXY_H_