Don't send touch move to renderer while scrolling

content/browser/renderer_host/touch_event_queue.cc

 // Copyright (c) 2012 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/touch_event_queue.h"
 
 #include "base/stl_util.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/port/browser/render_widget_host_view_port.h"
@@ skipping 151 matching lines @@
 const WebKit::WebTouchEvent& TouchEventQueue::GetLatestEvent() const {
   return touch_queue_.back()->coalesced_event();
 }
 
 void TouchEventQueue::PopTouchEventToView(InputEventAckState ack_result) {
   if (touch_queue_.empty())
     return;
   scoped_ptr<CoalescedWebTouchEvent> acked_event(touch_queue_.front());
   touch_queue_.pop_front();
 
+  WebKit::WebInputEvent::Type event_type = acked_event->coalesced_event().type;
+  if (event_type == WebKit::WebInputEvent::TouchCancel &&
+      render_widget_host_->skip_next_acked_touch_cancel()) {
+    render_widget_host_->skip_next_acked_touch_cancel() = false;
+    return;
+  }
+
   // Note that acking the touch-event may result in multiple gestures being sent
   // to the renderer.
   RenderWidgetHostViewPort* view = RenderWidgetHostViewPort::FromRWHV(
       render_widget_host_->GetView());
   for (WebTouchEventList::const_iterator iter = acked_event->begin(),
        end = acked_event->end();
        iter != end; ++iter) {
     view->ProcessAckedTouchEvent((*iter), ack_result);
   }
 }
 
 bool TouchEventQueue::ShouldForwardToRenderer(
     const WebKit::WebTouchEvent& event) const {
   // Touch press events should always be forwarded to the renderer.
   if (event.type == WebKit::WebInputEvent::TouchStart)
     return true;
 
+  // If scrolling is in progress, don't sned touch moves to renderer.
+  if (render_widget_host_->scroll_update_in_progress() &&
+      event.type == WebKit::WebInputEvent::TouchMove)
+    return false;
+
   for (unsigned int i = 0; i < event.touchesLength; ++i) {
     const WebKit::WebTouchPoint& point = event.touches[i];
     // If a point has been stationary, then don't take it into account.
     if (point.state == WebKit::WebTouchPoint::StateStationary)
       continue;
 
     if (touch_ack_states_.count(point.id) > 0) {
       if (touch_ack_states_.find(point.id)->second !=
           INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS)
         return true;
     } else {
       // If the ACK status of a point is unknown, then the event should be
       // forwarded to the renderer.
       return true;
     }
   }
 
   return false;
 }
 
 }  // namespace content