[Android] Disable fling cancel filtering in the GestureEventQueue

content/browser/renderer_host/input/gesture_event_queue.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/renderer_host/input/gesture_event_queue.h"
 
 #include "base/trace_event/trace_event.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
 #include "content/browser/renderer_host/input/touchscreen_tap_suppression_controller.h"
 
@@ skipping 36 matching lines @@
     gesture_transform.Translate(gesture_event.event.x, gesture_event.event.y);
   } else {
     NOTREACHED() << "Invalid event type for transform retrieval: "
                  << WebInputEventTraits::GetName(gesture_event.event.type);
   }
   return gesture_transform;
 }
 
 }  // namespace
 
-GestureEventQueue::Config::Config() {
+GestureEventQueue::Config::Config() : enable_fling_cancel_filtering(true) {
 }
 
 GestureEventQueue::GestureEventQueue(
     GestureEventQueueClient* client,
     TouchpadTapSuppressionControllerClient* touchpad_client,
     const Config& config)
     : client_(client),
+      enable_fling_cancel_filtering_(config.enable_fling_cancel_filtering),
       active_fling_count_(0),
       scrolling_in_progress_(false),
       ignore_next_ack_(false),
       touchpad_tap_suppression_controller_(
           touchpad_client,
           config.touchpad_tap_suppression_config),
       touchscreen_tap_suppression_controller_(
           this,
           config.touchscreen_tap_suppression_config),
       debounce_interval_(config.debounce_interval) {
@@ skipping 10 matching lines @@
       !ShouldForwardForGFCFiltering(gesture_event) ||
       !ShouldForwardForTapSuppression(gesture_event)) {
     return;
   }
 
   QueueAndForwardIfNecessary(gesture_event);
 }
 
 bool GestureEventQueue::ShouldDiscardFlingCancelEvent(
     const GestureEventWithLatencyInfo& gesture_event) const {
+  if (!enable_fling_cancel_filtering_)
+    return false;
+
   GestureQueue::const_reverse_iterator it =
       coalesced_gesture_events_.rbegin();
   while (it != coalesced_gesture_events_.rend()) {
     if (it->event.type == WebInputEvent::GestureFlingStart)
       return false;
     if (it->event.type == WebInputEvent::GestureFlingCancel)
       return true;
     it++;
   }
   // If there are no fling-affecting events in the queue, and there's still an
@@ skipping 284 matching lines @@
     return 0;
 
   if (!ignore_next_ack_)
     return 1;
 
   DCHECK_GT(coalesced_gesture_events_.size(), 1U);
   return 2;
 }
 
 }  // namespace content