events: Change gesture-event handler in EventHandler to not return any values.

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index b07a75c4b4aaec2a54988c515a7fc685534f2875..1d95d833b528c3543018a921b8b194eaff5d2a68 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -1164,7 +1164,7 @@ ui::EventResult Widget::OnScrollEvent(ui::ScrollEvent* event) {
       DispatchScrollEvent(event);
 }
 
-ui::EventResult Widget::OnGestureEvent(ui::GestureEvent* event) {
+void Widget::OnGestureEvent(ui::GestureEvent* event) {
   ScopedEvent scoped(this, *event);
   switch (event->type()) {
     case ui::ET_GESTURE_TAP_DOWN:
@@ -1185,8 +1185,7 @@ ui::EventResult Widget::OnGestureEvent(ui::GestureEvent* event) {
     default:
       break;
   }
-  return static_cast<internal::RootView*>(GetRootView())->
-      DispatchGestureEvent(event);
+  static_cast<internal::RootView*>(GetRootView())->DispatchGestureEvent(event);
 }
 
 bool Widget::ExecuteCommand(int command_id) {