Pass tap count (1 or 2) with tap gesture events

ui/base/gestures/gesture_types.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 "ui/base/gestures/gesture_types.h"
 
 namespace ui {
 
 GestureEventDetails::GestureEventDetails(ui::EventType type,
                                          float delta_x,
@@ skipping 21 matching lines @@
       CHECK_EQ(0.f, delta_y) << "Unknown data in delta_y for pinch";
       break;
 
     case ui::ET_GESTURE_MULTIFINGER_SWIPE:
       data.swipe.left = delta_x < 0;
       data.swipe.right = delta_x > 0;
       data.swipe.up = delta_y < 0;
       data.swipe.down = delta_y > 0;
       break;
 
+    case ui::ET_GESTURE_TAP:
+      data.tap_count = static_cast<int>(delta_x);
+      CHECK_EQ(0.f, delta_y) << "Unknown data in delta_y for tap.";
+      break;
+
     default:
       data.generic.delta_x = delta_x;
       data.generic.delta_y = delta_y;
       if (delta_x != 0.f || delta_y != 0.f) {
         DLOG(WARNING) << "A gesture event (" << type << ") had unknown data: ("
                       << delta_x << "," << delta_y;
       }
       break;
   }
 }
 
 }  // namespace ui