Don't drop mouse wheel events with phase ending information in RWHVCF.

content/browser/frame_host/render_widget_host_view_child_frame.cc

 // Copyright 2014 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/frame_host/render_widget_host_view_child_frame.h"
 
 #include <algorithm>
 #include <utility>
 #include <vector>
 
@@ skipping 470 matching lines @@
 
 void RenderWidgetHostViewChildFrame::ProcessMouseEvent(
     const blink::WebMouseEvent& event,
     const ui::LatencyInfo& latency) {
   host_->ForwardMouseEventWithLatencyInfo(event, latency);
 }
 
 void RenderWidgetHostViewChildFrame::ProcessMouseWheelEvent(
     const blink::WebMouseWheelEvent& event,
     const ui::LatencyInfo& latency) {
-  if (event.delta_x != 0 || event.delta_y != 0)
+  if (event.delta_x != 0 || event.delta_y != 0 ||
+      event.phase == blink::WebMouseWheelEvent::kPhaseEnded ||
+      event.phase == blink::WebMouseWheelEvent::kPhaseCancelled ||
+      event.momentum_phase == blink::WebMouseWheelEvent::kPhaseEnded ||
+      event.momentum_phase == blink::WebMouseWheelEvent::kPhaseCancelled)
     host_->ForwardWheelEventWithLatencyInfo(event, latency);
 }
 
 void RenderWidgetHostViewChildFrame::ProcessTouchEvent(
     const blink::WebTouchEvent& event,
     const ui::LatencyInfo& latency) {
   if (event.GetType() == blink::WebInputEvent::kTouchStart &&
       frame_connector_ && !frame_connector_->HasFocus()) {
     frame_connector_->FocusRootView();
   }
@@ skipping 213 matching lines @@
                                                       frame_sink_id_);
   }
   support_.reset();
 }
 
 bool RenderWidgetHostViewChildFrame::HasEmbedderChanged() {
   return false;
 }
 
 }  // namespace content