Wire up gesturetap in SkyShell

sky/services/viewport/input_event.mojom

Index: sky/services/viewport/input_event.mojom
diff --git a/sky/services/viewport/input_event.mojom b/sky/services/viewport/input_event.mojom
index 3e8461959f7a94ae963518f2a4f0367f5356e8a3..b89571e47b83f6a9a1a0cf366e7afc6fd7e1bc06 100644
--- a/sky/services/viewport/input_event.mojom
+++ b/sky/services/viewport/input_event.mojom
@@ -6,15 +6,19 @@ module sky;
 
 enum EventType {
   UNKNOWN,
+  POINTER_CANCEL,
   POINTER_DOWN,
-  POINTER_UP,
   POINTER_MOVE,
-  POINTER_CANCEL,
+  POINTER_UP,
+  GESTURE_FLING_CANCEL,
+  GESTURE_FLING_START,
+  GESTURE_LONG_PRESS,
   GESTURE_SCROLL_BEGIN,
-  GESTURE_SCROLL_UPDATE,
   GESTURE_SCROLL_END,
-  GESTURE_FLING_START,
-  GESTURE_FLING_CANCEL,
+  GESTURE_SCROLL_UPDATE,
+  GESTURE_SHOW_PRESS,
+  GESTURE_TAP,
+  GESTURE_TAP_DOWN,
 };
 
 enum PointerKind {
@@ -42,12 +46,12 @@ struct PointerData {
 };
 
 struct GestureData {
-    float x;
-    float y;
-    float dx;
-    float dy;
-    float velocityX;
-    float velocityY;
+  float x;
+  float y;
+  float dx;
+  float dy;
+  float velocityX;
+  float velocityY;
 };
 
 struct InputEvent {