Tiimer based phase info generated for mouse wheel events.

content/browser/renderer_host/render_widget_host_view_event_handler.h

 // Copyright 2016 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_EVENT_HANDLER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_EVENT_HANDLER_H_
 
 #include <memory>
 
 #include "base/macros.h"
+#include "base/timer/timer.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/events/event_handler.h"
 #include "ui/events/gestures/motion_event_aura.h"
 #include "ui/latency/latency_info.h"
 
 namespace aura {
 class Window;
 }  // namespace aura
 
 namespace blink {
 class WebMouseEvent;
 class WebMouseWheelEvent;
 class WebTouchEvent;
 }  // namespace blink
 
 namespace ui {
 class TextInputClient;
 class TouchSelectionController;
 }
 
 namespace content {
+
+// The duration after which a synthetic wheel with zero deltas and
+// phase = |kPhaseEnded| will be sent after the last wheel event.
+const int64_t kDefaultMouseWheelLatchingTransactionMs = 100;
+
 struct ContextMenuParams;
 class OverscrollController;
 class RenderWidgetHostImpl;
 class RenderWidgetHostViewBase;
 class TouchSelectionControllerClientAura;
 
 // Provides an implementation of ui::EventHandler for use with
 // RenderWidgetHostViewBase. A delegate is required in order to provide platform
 // specific functionality.
 //
@@ skipping 134 matching lines @@
   // Returns true when we can do SurfaceHitTesting for the event type.
   bool ShouldRouteEvent(const ui::Event* event) const;
 
   // Directs events to the |host_|.
   void ProcessMouseEvent(const blink::WebMouseEvent& event,
                          const ui::LatencyInfo& latency);
   void ProcessMouseWheelEvent(const blink::WebMouseWheelEvent& event,
                               const ui::LatencyInfo& latency);
   void ProcessTouchEvent(const blink::WebTouchEvent& event,
                          const ui::LatencyInfo& latency);
+  void SendSyntheticWheelEventWithPhaseEnded(
+      blink::WebMouseWheelEvent last_mouse_wheel_event,
+      bool should_route_event);
+  void AddPhaseAndScheduleEndEvent(blink::WebMouseWheelEvent& mouse_wheel_event,
+                                   bool should_route_event);
 
   // Whether return characters should be passed on to the RenderWidgetHostImpl.
   bool accept_return_character_;
 
   // Allows tests to send gesture events for testing without first sending a
   // corresponding touch sequence, as would be required by
   // RenderWidgetHostInputEventRouter.
   bool disable_input_event_router_for_testing_;
 
   // While the mouse is locked, the cursor is hidden from the user. Mouse events
@@ skipping 42 matching lines @@
   // The following are not owned. They should outlive |this|
   RenderWidgetHostImpl* const host_;
   // Should create |this| and own it.
   RenderWidgetHostViewBase* const host_view_;
   // Optional, used to redirect events to a popup and associated handler.
   RenderWidgetHostViewBase* popup_child_host_view_;
   ui::EventHandler* popup_child_event_handler_;
   Delegate* const delegate_;
   aura::Window* window_;
 
+  base::OneShotTimer mouse_wheel_end_dispatch_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewEventHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_EVENT_HANDLER_H_