Remove canScroll from WebMouseWheelEvent as it is unused now.

content/browser/renderer_host/input/mouse_wheel_event_queue.cc

 // 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.
 
 #include "content/browser/renderer_host/input/mouse_wheel_event_queue.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "base/trace_event/trace_event.h"
 
@@ skipping 62 matching lines @@
     const LatencyInfo& latency_info) {
   TRACE_EVENT0("input", "MouseWheelEventQueue::ProcessMouseWheelAck");
   if (!event_sent_for_gesture_ack_)
     return;
 
   event_sent_for_gesture_ack_->latency.AddNewLatencyFrom(latency_info);
   client_->OnMouseWheelEventAck(*event_sent_for_gesture_ack_, ack_result);
 
   // If event wasn't consumed then generate a gesture scroll for it.
   if (ack_result != INPUT_EVENT_ACK_STATE_CONSUMED &&
-      event_sent_for_gesture_ack_->event.canScroll &&
+      WebInputEventTraits::CanCauseScroll(event_sent_for_gesture_ack_->event) &&
       event_sent_for_gesture_ack_->event.resendingPluginId == -1 &&
       (scrolling_device_ == blink::WebGestureDeviceUninitialized ||
        scrolling_device_ == blink::WebGestureDeviceTouchpad)) {
     WebGestureEvent scroll_update;
     scroll_update.timeStampSeconds =
         event_sent_for_gesture_ack_->event.timeStampSeconds;
 
     scroll_update.x = event_sent_for_gesture_ack_->event.x;
     scroll_update.y = event_sent_for_gesture_ack_->event.y;
     scroll_update.globalX = event_sent_for_gesture_ack_->event.globalX;
@@ skipping 189 matching lines @@
   scroll_begin.data.scrollBegin.targetViewport = false;
   scroll_begin.data.scrollBegin.deltaHintUnits =
       gesture_update.data.scrollUpdate.deltaUnits;
 
   needs_scroll_begin_ = false;
   needs_scroll_end_ = true;
   client_->ForwardGestureEventWithLatencyInfo(scroll_begin, ui::LatencyInfo());
 }
 
 }  // namespace content