Consolidate WebInputEvent coalescing logic

content/port/browser/event_with_latency_info.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 CONTENT_PORT_BROWSER_EVENT_WITH_LATENCY_INFO_H_
 #define CONTENT_PORT_BROWSER_EVENT_WITH_LATENCY_INFO_H_
 
 #include "ui/events/latency_info.h"
 
+#include "content/common/input/web_input_event_traits.h"
+
 namespace WebKit {
 class WebGestureEvent;
 class WebMouseEvent;
 class WebMouseWheelEvent;
 class WebTouchEvent;
 }
 
 namespace content {
 
 template <typename T>
 class EventWithLatencyInfo {
  public:
   T event;
   ui::LatencyInfo latency;
 
   EventWithLatencyInfo(const T& e, const ui::LatencyInfo& l)
       : event(e), latency(l) {}
 
   EventWithLatencyInfo() {}
+
+  bool CanCoalesceWith(const EventWithLatencyInfo& other)
+      const WARN_UNUSED_RESULT {
+    return WebInputEventTraits::CanCoalesce(other.event, event);
+  }
+
+  void CoalesceWith(const EventWithLatencyInfo& other) {
+    WebInputEventTraits::Coalesce(other.event, &event);
+    latency.MergeWith(other.latency);
+  }
 };
 
 typedef EventWithLatencyInfo<WebKit::WebGestureEvent>
     GestureEventWithLatencyInfo;
 typedef EventWithLatencyInfo<WebKit::WebMouseWheelEvent>
     MouseWheelEventWithLatencyInfo;
 typedef EventWithLatencyInfo<WebKit::WebMouseEvent>
     MouseEventWithLatencyInfo;
 typedef EventWithLatencyInfo<WebKit::WebTouchEvent>
     TouchEventWithLatencyInfo;
 
 }  // namespace content
 
 #endif  // CONTENT_PORT_BROWSER_EVENT_WITH_LATENCY_INFO_H_