Fix gesture events in fn2

This CL makes gesture events work again in fn2.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1146923005

examples/fn2/container.dart

@@ -38,12 +38,17 @@ class ContainerApp extends App {
                   ),
               ])),
       ]),
-      onPointerDown: _handlePointerDown);
+      onPointerDown: _handlePointerDown,
+      onGestureTap: _handleGestureTap);
   }
 
   void _handlePointerDown(sky.PointerEvent event) {
     print("_handlePointerDown");
   }
+
+  void _handleGestureTap(sky.GestureEvent event) {
+    print("_handleGestureTap");
+  }
 }
 
 void main() {

examples/game/lib/sprite_box.dart

@@ -41,7 +41,7 @@ class SpriteBox extends RenderBox {
     size = constraints.constrain(new Size.infinite());
   }
 
-  void handlePointer(PointerEvent event) {
+  void handleEvent(Event event) {
     switch (event.type) {
       case 'pointerdown':
         print("pointerdown");

examples/raw/ink_well.dart

@@ -41,7 +41,7 @@ class InkSplash {
 class InkWell extends RenderBox {
   final List<InkSplash> _splashes = new List<InkSplash>();
 
-  void handlePointer(sky.PointerEvent event) {
+  void handleEvent(sky.Event event) {
     switch (event.type) {
       case 'pointerdown':
         _splashes.add(new InkSplash(position: new sky.Point(event.x, event.y),

examples/raw/sector_layout.dart

@@ -482,7 +482,7 @@ class RenderSolidColor extends RenderDecoratedSector {
     deltaTheta = constraints.constrainDeltaTheta(desiredDeltaTheta);
   }
 
-  void handlePointer(sky.PointerEvent event) {
+  void handleEvent(sky.Event event) {
     if (event.type == 'pointerdown')
       decoration = new BoxDecoration(backgroundColor: const sky.Color(0xFFFF0000));
     else if (event.type == 'pointerup')

examples/raw/touch_demo.dart

@@ -42,7 +42,7 @@ class RenderTouchDemo extends RenderBox {
 
   RenderTouchDemo();
 
-  void handlePointer(PointerEvent event) {
+  void handleEvent(sky.Event event) {
     switch (event.type) {
       case 'pointerdown':
         int color = colors[event.pointer.remainder(colors.length)];

examples/stocks2/lib/stock_app.dart

@@ -164,7 +164,7 @@ class StocksApp extends App {
     return new ToolBar(
         left: new IconButton(
           icon: 'navigation/menu_white',
-          onGestureTap: (_) => _drawerController.toggle),
+          onGestureTap: _drawerController.toggle),
         center: new Text('Stocks'),
         right: [
           new IconButton(