Support tap_count in ui::GestureProvider.

ui/events/gesture_detection/gesture_detector.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.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include "ui/events/gesture_detection/gesture_detector.h"
 
 #include <cmath>
@@ skipping 169 matching lines @@
       defer_confirm_single_tap_(false),
       in_longpress_(false),
       always_in_tap_region_(false),
       always_in_bigger_tap_region_(false),
       two_finger_tap_allowed_for_gesture_(false),
       is_double_tapping_(false),
       last_focus_x_(0),
       last_focus_y_(0),
       down_focus_x_(0),
       down_focus_y_(0),
-  longpress_enabled_(true),
-  swipe_enabled_(false),
-  two_finger_tap_enabled_(false) {
+      longpress_enabled_(true),
+      swipe_enabled_(false),
+      two_finger_tap_enabled_(false) {
   DCHECK(listener_);
   Init(config);
 }
 
 GestureDetector::~GestureDetector() {}
 
 bool GestureDetector::OnTouchEvent(const MotionEvent& ev) {
   const MotionEvent::Action action = ev.GetAction();
 
   velocity_tracker_.AddMovement(ev);
@@ skipping 309 matching lines @@
 void GestureDetector::OnTapTimeout() {
   if (!double_tap_listener_)
     return;
   if (!still_down_)
     double_tap_listener_->OnSingleTapConfirmed(*current_down_event_);
   else
     defer_confirm_single_tap_ = true;
 }
 
 void GestureDetector::Cancel() {
-  timeout_handler_->Stop();
+  CancelTaps();
   velocity_tracker_.Clear();
-  is_double_tapping_ = false;
   still_down_ = false;
-  always_in_tap_region_ = false;
-  always_in_bigger_tap_region_ = false;
-  defer_confirm_single_tap_ = false;
-  in_longpress_ = false;
 }
 
 void GestureDetector::CancelTaps() {
   timeout_handler_->Stop();
   is_double_tapping_ = false;
   always_in_tap_region_ = false;
   always_in_bigger_tap_region_ = false;
   defer_confirm_single_tap_ = false;
   in_longpress_ = false;
 }
 
 bool GestureDetector::IsConsideredDoubleTap(
     const MotionEvent& first_down,
     const MotionEvent& first_up,
     const MotionEvent& second_down) const {
   if (!always_in_bigger_tap_region_)
     return false;
 
   if (second_down.GetEventTime() - first_up.GetEventTime() >
       double_tap_timeout_)
     return false;
 
   const float delta_x = first_down.GetX() - second_down.GetX();
   const float delta_y = first_down.GetY() - second_down.GetY();
   return (delta_x * delta_x + delta_y * delta_y < double_tap_slop_square_);
 }
 
 }  // namespace ui