Suppress LongPress/Tap, and TwoFingerTap when TapDown cancels a fling.

content/browser/renderer_host/input/input_router_config_helper.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/input_router_config_helper.h"
 
 #include "base/command_line.h"
 #include "build/build_config.h"
 #include "content/public/common/content_switches.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
@@ skipping 31 matching lines @@
   ui::GestureConfiguration* gesture_config =
       ui::GestureConfiguration::GetInstance();
   config.debounce_interval = base::TimeDelta::FromMilliseconds(
       gesture_config->scroll_debounce_interval_in_ms());
 
   config.touchscreen_tap_suppression_config.enabled =
       gesture_config->fling_touchscreen_tap_suppression_enabled();
   config.touchscreen_tap_suppression_config.max_cancel_to_down_time =
       base::TimeDelta::FromMilliseconds(
           gesture_config->fling_max_cancel_to_down_time_in_ms());
+
+  // Tap suppression controller forwards the stashed tapDown and drops the rest
+  // of the stashed events when the tapDownTimer expires. If a fling cancel ack
+  // with |processed = false| arrives before the timer expiration, all stashed
+  // events will be forwarded. The timer is used to avoid waiting for an
+  // arbitrarily late fling cancel ack. Its delay should be large enough for
+  // a long press to get stashed and forwarded if needed.
   config.touchscreen_tap_suppression_config.max_tap_gap_time =
       base::TimeDelta::FromMilliseconds(
-          gesture_config->long_press_time_in_ms());
+          gesture_config->long_press_time_in_ms() + 50);
 
   config.touchpad_tap_suppression_config.enabled =
       gesture_config->fling_touchpad_tap_suppression_enabled();
   config.touchpad_tap_suppression_config.max_cancel_to_down_time =
       base::TimeDelta::FromMilliseconds(
           gesture_config->fling_max_cancel_to_down_time_in_ms());
   config.touchpad_tap_suppression_config.max_tap_gap_time =
       base::TimeDelta::FromMilliseconds(
           gesture_config->fling_max_tap_gap_time_in_ms());
 
   return config;
 }
 
 }  // namespace
 
 InputRouterImpl::Config GetInputRouterConfigForPlatform() {
   InputRouterImpl::Config config;
   config.gesture_config = GetGestureEventQueueConfig();
   config.touch_config = GetTouchEventQueueConfig();
   return config;
 }
 
 }  // namespace content