Wheel scroll latching enabled behind flag.

content/browser/renderer_host/input/input_router_impl.cc

 // 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.
 
 #include "content/browser/renderer_host/input/input_router_impl.h"
 
 #include <math.h>
 
 #include <utility>
 
@@ skipping 11 matching lines @@
 #include "content/common/edit_command.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/common/input/touch_action.h"
 #include "content/common/input/web_input_event_traits.h"
 #include "content/common/input/web_touch_event_traits.h"
 #include "content/common/input_messages.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/user_metrics.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "ipc/ipc_sender.h"
 #include "ui/events/blink/blink_event_util.h"
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 
 using base::Time;
 using base::TimeDelta;
 using base::TimeTicks;
 using blink::WebGestureEvent;
@@ skipping 35 matching lines @@
       ack_handler_(ack_handler),
       routing_id_(routing_id),
       frame_tree_node_id_(-1),
       select_message_pending_(false),
       move_caret_pending_(false),
       mouse_move_pending_(false),
       current_ack_source_(ACK_SOURCE_NONE),
       flush_requested_(false),
       active_renderer_fling_count_(0),
       touch_scroll_started_sent_(false),
-      wheel_event_queue_(this, kDefaultWheelScrollTransactionMs),
+      wheel_event_queue_(
+          this,
+          base::FeatureList::IsEnabled(features::kTouchpadScrollLatching)
+              ? kDefaultWheelScrollLatchingTransactionMs
+              : kDefaultWheelScrollTransactionMs),
       touch_event_queue_(this, config.touch_config),
       gesture_event_queue_(this, this, config.gesture_config),
       device_scale_factor_(1.f) {
   DCHECK(sender);
   DCHECK(client);
   DCHECK(ack_handler);
   UpdateTouchAckTimeoutEnabled();
 }
 
 InputRouterImpl::~InputRouterImpl() {
@@ skipping 550 matching lines @@
 
   flush_requested_ = false;
   client_->DidFlush();
 }
 
 void InputRouterImpl::SetFrameTreeNodeId(int frameTreeNodeId) {
   frame_tree_node_id_ = frameTreeNodeId;
 }
 
 }  // namespace content