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

ui/views/controls/button/menu_button.cc

Index: ui/views/controls/button/menu_button.cc
diff --git a/ui/views/controls/button/menu_button.cc b/ui/views/controls/button/menu_button.cc
index 601726a5445450bebfb299952f2aa06e64290f0e..b770a6496886bab87e286677423be14033538bce 100644
--- a/ui/views/controls/button/menu_button.cc
+++ b/ui/views/controls/button/menu_button.cc
@@ -219,13 +219,13 @@ void MenuButton::OnMouseExited(const ui::MouseEvent& event) {
   }
 }
 
-ui::EventResult MenuButton::OnGestureEvent(ui::GestureEvent* event) {
+void MenuButton::OnGestureEvent(ui::GestureEvent* event) {
   if (state() != STATE_DISABLED && event->type() == ui::ET_GESTURE_TAP) {
     if (Activate())
-      return ui::ER_CONSUMED;
-    return ui::ER_UNHANDLED;
+      event->StopPropagation();
+    return;
   }
-  return TextButton::OnGestureEvent(event);
+  TextButton::OnGestureEvent(event);
 }
 
 bool MenuButton::OnKeyPressed(const ui::KeyEvent& event) {