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

ui/base/gestures/gesture_types.h

Index: ui/base/gestures/gesture_types.h
diff --git a/ui/base/gestures/gesture_types.h b/ui/base/gestures/gesture_types.h
index 56dad14df12890f0aa970cb0369c9c457f4f71ac..b84faeecb61d45104c6b95bcf3016c582cf52f5b 100644
--- a/ui/base/gestures/gesture_types.h
+++ b/ui/base/gestures/gesture_types.h
@@ -69,12 +69,9 @@ struct UI_EXPORT GestureEventDetails {
     return data.swipe.down;
   }
 
-  float generic_x() const {
-    return data.generic.delta_x;
-  }
-
-  float generic_y() const {
-    return data.generic.delta_y;
+  int tap_count() const {
+    CHECK_EQ(ui::ET_GESTURE_TAP, type_);
+    return data.tap_count;
   }
 
  private:
@@ -101,6 +98,8 @@ struct UI_EXPORT GestureEventDetails {
       bool down;
     } swipe;
 
+    int tap_count;  // TAP repeat count.
+
     struct {
       float delta_x;
       float delta_y;